Nerd Experience

trim() not supported by IE7 and IE8

2012-01-27T03:03:00.000-08:00

Funny fact, trim function is not supported by IE7 and IE8.

Ok, it is supported, but through jQuery trim function.
So, when you have something like this:

jQuery(...).attr().trim()

, this trim() function stops having any relation to jQuery, as the attr() would return String type, which method would be then trim(). Since IE7 and IE8 do not support trim() method within String type, you should use instead

jQuery.trim(jQuery(...).attr())

or if you don't wanna use jQuery (whyyyy?), you can simply implement the trim function youself.

if(typeof String.prototype.trim !== 'function') {
String.prototype.trim = function() {
return this.replace(/^\s+|\s+$/g, '');
}
}

http://www.blogger.com/img/blank.gif
source 1
source 2

Testing developments for different versions of Internet Explorer

2012-01-27T02:16:00.000-08:00

I found excellent article on development environments different IE versions review, made By Addy Osmani

Article can be found here

I usually tend to take all the context from the page into this blog to make sure it exist also after the page disappears (you will be surprised how fast linkhttp://www.blogger.com/img/blank.gifs gets changed, wither due to change of the link itself, or to site being closed down due to whatever reasons). This time I'll give it a risk.

Just as a summary, for fast and simple testing, use F12 development mode, and for more detailed test, use the virtual machines and IECollection (you have to get yourself licensed versions of Windows (XP, Vista, and 7)), or use the Windows Virtual PC VHDs (read Notes, max 90 days of being able to permanently save any changes, made on the images).

As a long time user of Virtual machines, I do like to use virtual machines, like VMware or VirtualBox, but still, the easiest way so far is to use F12 developer mode button on IE, and set the browser version to one you require.

tabindex browser compatibility issue

2012-01-25T03:21:00.000-08:00

When creating form, take care of the way how the fields are passed on when key is pressed. It is usually solved via tabindex, being set as an attribute to the form fields.
However, if some of the elements in the following set {A, AREA, BUTTON, INPUT, OBJECT, SELECT, and TEXTAREA} are not tabindexed, browsers will behave differently upon them.

Internet Explorer will make them first in the order, and then those which are tabindexed, and Firefox would do opposite. Therefore you can either put to not tabindexed elements very large value (up to 32545), so they are shown always the last, or put tabindex="-1". I personally would not use the latter case, as it is not valid value for tabindex in its defition, so the browsers might change the way they behave upon it in the future.

Some more details about it, I have found pretty nice article:
http://www.codestore.net/store.nsf/unid/BLOG-20060706

Triggering event in a Form/Javascript

2012-01-24T07:55:00.001-08:00

Sometimes the values you put in the form through any kind of way except user interaction are not triggering change event upon which some other parts of the form behave. In order to forcefully trigger the even, you can use jQuery.
jQuery('YOUR_SELECTOR').trigger('change');
or simply
$('YOUR_SELECTOR').trigger('change');

My Advice. ALWAYS use jQuery rather than any custom made functions, since jQuery is guaranteed to be web browser compatible! And it is cool and easy!

Problem of Spring using ISO9968-1 instead of UTF8

2012-01-22T11:11:00.001-08:00

After a long search for a solution, a friend of mine gave me this solution.
Put on top of each jsp file the following two lines:
<%@ page contentType="text/html; charset=UTF-8" %>
<%@ page pageEncoding="UTF-8" %>

Get the current path of the web project - alternative way

2012-01-19T03:08:00.001-08:00

This alternative way to get absolute path for some of the things, is useful when you need to read or write a some project related file and use it later again.

File file=new File(.class.getClassLoader().getResource("WEB-INF/").getFile());
System.out.println("path is:"+file.getAbsolutePath());

Prevent JAXB from creating JAXBElements

2012-01-18T06:30:00.000-08:00

I had some annoying trouble with updating JAXB1.0 code into JAXB2.0 code, among which the one of the things is the generation og JAXBElements instead normal type, like JAXBElements instead of simple double.
This is due to fact that JAXB wants to define cases of elements in XSD with minOccurs="0" and nillable="true". If you don't care about such issue, then you can prevent JAXB from creating the JAXBElements in a following way:

Add to your command line generation -b addCFG.xjb
where addCFG.xjb is this file:
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:jaxb="http://java.sun.com/xml/ns/jaxb"
jaxb:version="2.0">

source:

Process Explorer

2012-01-18T06:21:00.000-08:00

(Windows related)

There is a nice additional utility from Microsoft, for regulating problems/stuff in windows. This utility is sort of a advanced version of task manager, just muuuch better.

It's called the Process Explorer, and it has number many additional features among which these are probably most interesting for regular users:
- Actual view of all the applications that are running
- list of handles opened - this is especially useful when some of programs have closed the connection opened towards peripherals, like removable media (USB stick, flash stick, camera, etc.)

Timeline on Latex

2011-06-15T01:01:00.001-07:00

One of nicer looking timeline graphs for Latex is by using the chronology package

This is the example:
\usepackage{chronology}
...
\begin{chronology}[5]{1983}{2010}{3ex}{\textwidth}
\event{1984}{one}
\event[1985]{1986}{two}
\event{\decimaldate{25}{12}{2001}}{three}
\end{chronology}

source.

Installing new package in Latex

2011-06-15T00:59:00.000-07:00

If you are using linux, the TeX Live is installed on:

/usr/share/texmf-texlive/tex/latex

To install a style file you have to create a directory for it and copy the contents there. Next you have to run the program mktexlsr as root.

Bulk renaming in Debian Linux

2011-05-16T11:29:00.001-07:00

The simplest way to this is using a perl script called rename (debian linux only)

I used only substitute strings, but it fully supports filenames which is really cool :)

rename -v 's/oldString/newString/' *.htm

Two sources for this:
http://tips.webdesign10.com/how-to-bulk-rename-files-in-linux-in-the-terminal
http://www.troubleshooters.com/codecorn/littperl/perlreg.htm

Case sensitive stuff and figures in latex

2011-02-26T09:40:00.000-08:00

I had some troubles to link the latex sources done in windows (case insensitive) to compile on linux (case sensitive). In order to fastly solve this problem, first, I run in shell (simply copy/paste in terminal) following code to make all figure files lowercase. This code works only for current directory.

for f in *; do
g=`expr "xxx$f" : 'xxx$.*$' | tr '[A-Z]' '[a-z]'`
mv "$f" "$g"
done

However, I found a bit difficult part to rename all the figure links within latex to lowercase. At least not without coding. I didnt have time to check the possibility to edit the code above to so it could be used also within files, but when I come up to this issue again, I might reedit this post.

X forwarding: Took me long for this discovery :)

2011-02-10T02:50:00.000-08:00

VNC works usually pretty well to control PCs remotely. However, sometimes you only want to run just one program from the remote PC (or 64-core server), like matlab.
Better option than VNC is definitely X forwarding.

ssh -l username -X -v servername

Once you login, simply just run the command for your program, and it will be open like a regular program :)

More details on:
http://www.vanemery.com/Linux/XoverSSH/X-over-SSH2.html

There is also a possibility to do the same in windows using putty and Xwin32:
http://www.math.umn.edu/systems_guide/putty_xwin32.html

edit: In order to enable the X forwarding on your own machine, do the following (ubuntu 11.10)

1) Install openssh-server
“sudo apt-get install openssh-server”

2) Edit the file /etc/ssh/ssh_config. Find/uncomment/modify these lines:
ForwardAgent yes
ForwardX11 yes
ForwardX11Trusted yes

3) Edit /etc/ssh/sshd_config. Find/uncomment/modify these lines:
X11Forwarding yes

4) Restart your SSH server.
Earlier, you were playing with init.d, now in Ubuntu it is advised to use this instead:
"sudo service ssd restart"

source: http://www.craigryder.com/linux-ubuntudebetc/x11-forwarding-and-ssh-for-remote-linux-ubuntu-desktop/

Parallel processing, yiha :)

2010-08-04T00:55:00.000-07:00

So, you have some very high computation-demanding work to do? Furthermore, you also have some fancy server with 16 cores or more, all available for your sexy computations?
Cool, then you would LOVE the ppss.
What it does is that it can scan for you how many cores has the machine that runs ppss, and schedules list of processes to each of the cores.
For example, I have around 200 separate simulations to perform.
I downloaded ppss (no compilation necessary :) ), and just run it with specific command (help can be found on link above).

It reduced the running time of my simulations from 2 weeks to 2 days :)

Turn off the windows automatic updates

2010-08-04T00:52:00.001-07:00

I am one of those people who don't like to turn off their PCs. Yea, really nice waste of energy, I know...

Usually work PC is the place when always something is running overnight, either some sort of calculations, parsing, simulations or any other nerdy stuff.

The most annoying part, when you work on windows, are the automatic updates. It can restart your PC by itself just to apply just installed updates. "§$%&%$ windows!

In order to disable such a stupid option,
Go to Start, Run "gpedit.msc" to bring up the group policy editor.
Then navigate to the folder

Local Computer Policy
->Computer Configuration
->Administrative Templates
->Windows Components
->Windows Update

There are two settings and both will work, so it's your choice. Either enable No auto-restart for schedule Automatic Updates installations or set Re-prompt for restart with scheduled installations to a long time interval, like 1440 minutes.

I prefer the first one :)

Running a process that doesnt get killed on hangup

2010-05-13T08:05:00.001-07:00

If you want to run a process on a server you are remotely connected to, without getting it disturbed if you close your SSH/telnet connection to a server, you should use command nohup

example:
nohup your_command &

& puts it into backgroung process, and nohup is a POSIX command to ignore the HUP (hangup) signal, enabling the command to keep running after the user who issues the command has logged out.

TOSSIM Python compiling problem

2010-04-29T10:43:00.000-07:00

When you use TOSSIM in TinyOS, you come up to this error:

In function ‘void SWIG_Python_FixMethods(PyMethodDef*, swig_const_info*, swig_type_info**, swig_type_info**)’
error: invalid conversion from ‘const char*’ to ‘char*’

(overall there are two errors like this one)

First check whether the error can be solved using solution on TinyOS wiki website on
TOSSIM .

If even than, it doesn't work,
go to $TOSROOT/tos/lib/tossim and run ./generate-swig.bash
In my case, it shows you some warnings, but that is ok.
afterwards, it worked fine for me.

If you still have troubles, check also:
python and python-dev should be on the same version,
swig should be installed.

If all this didnt solve your problems, good luck finding it, and I hope you put the solution somewhere on internet as well.

Debugging QUALNET with GDB

2010-03-26T11:57:00.000-07:00

Compiling QualNet with Debug Option
By default, the optimization option of the compiler is enabled in the Linux and Mac OS X Makefiles. When the optimization option is enabled, the compiler may optimize the program for better performance. However, for better source level debugging, the optimization option of the compiler should be disabled and the debug option should be enabled.
Perform following steps to recompile QualNet with the debug option enabled:
1. Go to QUALNET_HOME/main. Copy the makefile for your compiler to Makefile.
2.Edit Makefile as follows:
•Enable the DEBUG line by removing the ‘#’ character so it is displayed as:
DEBUG = -g
•Disable the OPT line by inserting a ‘#’ character at the beginning of the line so it is displayed as:
# OPT = -O3
3.Recompile QualNet by typing the following commands:
make clean
make

Running the Debugger
QualNet can be run from within debug tools such as gdb or dbx. Here, we use gdb as an example.
To run gdb, perform the following steps:
1. Open a command window. Go to the directory where the scenario to be debugged is located.
2.Load the QualNet executable into gdb by typing the following command (this assumes that QualNet is installed in /home/username/qualnet/5.0):
gdb /home/username/qualnet/5.0/bin/qualnet
3.From within the gdb environment, run your scenario in gdb by typing the following command (assuming the scenario configuration file is myscenario.config):
run myscenario.config
4.To exit gdb, type following command in gdb:
quit
Refer to gdb user manual for more information on how to debug a program in gdb.

Taken from https://www.scalable-networks.com/boards/viewtopic.php?f=47&t=4833&start=0

To get the value of the current variables use
print name_of_the_variable

To see where the function is called from:
backtrace

Regular expression for the functions

2010-03-12T14:28:00.000-08:00

If you wanna have something like

int thisFunction(int a,
int b)
{

to be turned into

int thisFunction(int a,
int b)
{
printf("thisFunction Started");

You can search for functions using the following regular expression:

[[a-zA-Z0-9_-]+[\s]+]?[a-zA-Z0-9_-]+[*]?[\s]+[*]?([a-zA-Z0-9_-*]+)[\s]*$[\s]*([a-zA-Z0-9_-]+[\s]+[*]?[*]?[*]?[a-zA-Z0-9_-]+[,]?[\s]*)*$[\s]*\{

update:

(static)?[\s]+(//inline//[\s]*)?[a-zA-Z0-9_-]+[*]?[*]?[\s]+([^\s$]+)[\s]*\([^$=]*\)[\s]*\{

Replace with:

\0 // \1 Started\r\nprintf("\1 Started");

update:

\0 // \3 Started\r\nprintf("\3 Started");

"Reverse Engineering" in different programming languages?

2010-02-20T02:32:00.000-08:00

A lot of engineers in one point of another needs to look through usually undocumented open source code, in order to modify/implement additional features. Using editor for bigger projects built in C/C++ (without OOP) can be unbelievably painful (my own experience). Two software that helped me a lot to reverse engineer my any source code are:

1) Doxygen: Creates nice documentation of all the functions in the project. It gives links to definition of each function, but more interesting is also can create call/caller graphs (for each function it gives graph of functions which it calls, and another graph of the function which call that function).
It is completely a freeware, and the graphs are done using the dot program.

2) Understand: the free trial version of this application (14 days) is very handy, and is a bit more powerful comparing to Doxygen.

Multiline Regular Expressions

2009-07-02T04:33:00.000-07:00

There are a lot of text editors that offer regular expression search and replace, but rare are those that support multiline regular expressions. In my case I need to find all the function headers with starting body bracket.
example:
"int a(int b, int c)
{"

should be changed with
"int a(int b, int c)
{
printf("Entered function a");"

Text editor that supports such thing is called "EditPad Pro". Besides multiline regular expression support, it also have coloring system for your regular expression, so u can debug your regex easier.

To be edited with regular expressions that solved my problem

Same useful links while learning TinyOS

2009-06-18T06:30:00.001-07:00

http://www.eecs.iu-bremen.de/wiki/index.php/TinyOS

Changing parameters in TinyOS via Makefile

2009-06-18T03:25:00.000-07:00

Changing the Radio channel
- Radio channel numbers have range between 11 to 26
- Add the following line in the Makefile before the Makerules
CC2420_CHANNEL=x where x = [11 26]
Changing the Radio Transmit power
- Transmit power valid levels are 1 to 31 with power 1 equals to -25dBm and 31 equals to max (0dBm)
- add the following line in the Makefile before the Makerules
CFlags = -DCC2420_DEF_RFPower= x where x = [1 31]

Changing the Active message group ID
Add DEFAULT_LOCAL_GROUP = X to the makefile where X = [0×10 0×50]

Working with floating point in TinyOS

2008-11-21T05:30:00.000-08:00

There are two ways to represent float in nesc.
One way, is to do it through by convention using the exponent and mantissa,
where you need to use 2^exponent. The function that does that is called powf().
The problem with using that function is that it is reaaaaallly slow.
[QUOTE]
----8<----
DbgOut_P20_ON;
r = logf((float)v / 10000.0); // takes up about 10 ms (!!)
DbgOut_P20_OFF;
----8<----

and a
----8<----
DbgOut_P20_ON;
r = powf(10,(float)v / 10000.0); // takes up about 32 ms (!!!!!!)
DbgOut_P20_OFF;
----8<----
[/QUOTE]

In case you need to have fast response, this function might not be your choice.
One way to optimize the speed of those operations are:
"I'd like to mention that pow(a,b) is MUCH harder to implement than
exp(b). Use the latter whenever possible. In particular, if a is
fixed, use exp(b * log(a)) rather than pow(a,b). (In fact, that's a
common low-precision implementation technique even when a is not fixed.)

Also note that keeping logarithms in fixed-point format is often
convenient, and shaves a bit of overhead from the code when you
don't have hardware floating-point. "

One quite dirty trick to show real numbers in nesc is to define fix point.
for example in 16 bits, you say 12 bits are the bits before the decimal point, and 4 bits are bits after the point. a(12bits) + ( b(4bits)/16 ).
This dirty trick is good in case one wants working with float go faster, without need for much precision.

File Sharing between to PCs under Windows

2008-11-05T03:07:00.000-08:00

Several times I badly needed the connection between to PCs and I never actually managed to make it working :(

One thing I always forget to set is that both PCs have the same Workgroup, besides the part where you set your folder to be shared among PCs in the network.

Finally, clear explanation of TinyOS 2.x serial packet structure

2008-06-05T03:37:00.001-07:00

TinyOS 2.x

A message sent through serial ports from motes to PC will typically look like this:

00 FF FF 00 00 08 00 09 19 77 02 07 00 13 00 00

The first byte 00 is the leading zero.
After that, the whole packet is of the type "serial_packet_t", defined in tinyos-2.x/tos/lib/serial/Serial.h.

Inside the serial_packet_t structure, the first 7 bytes are of the type "serial_header_t", which is also defined in tinyos-2.x/tos/lib/serial/Serial.h.

In the case above, it would be FF FF 00 00 08 00 09.

Within the "serial_header_t", the following structure takes place:

nx_am_addr_t dest // Destination (2 bytes)
nx_am_addr_t src // Source (2 bytes)
nx_uint8_t length // Payload Length (1 byte)
nx_am_group_t group // Group ID (1 byte)
nx_am_id_t type // Active Message Handler Type (1 byte), some enum value that you can define yourself.

After the 7 byte header, here comes the payload, which can be up to TOS_DATA_LENGTH (28 bytes) long. The content could be anything.

In the above example, the payload is: 19 77 02 07 00 13 00 00, which is of the length (8 bytes) denoted in the "Payload Length" field.

To note, besides the payload part, we need to fill out the destination address and payload length field by calling SerialActiveMessageC.AMSend(am_addr_t dest, message_t* msg, uint8_t len). It would be a good programming manner to fill the len with sizeof(). And we also need to specify the Active Message Handler Type by wiring the AMSend to SerialActiveMessage.AMSend[am_id_t id];

ref:
http://www.tinyos.net/tinyos-2.x/doc/html/tutorial/lesson4.html. The doc here doesn't seem to be up-to-date since it left out the source address from the header.

GREAT THANKS TO http://tristan-tech.blogspot.com/ and his blog!!!!

(I copied whole blog from him in order to have in mine blog everything I might use in future)

2008-04-25T05:10:00.000-07:00

Some really nice people has made cool Linux Live CD which has TinyOS installed.
Really cool for people who need the TinyOS fast!
This is the version with TinyOS 2.x
http://toilers.mines.edu/Public/XubunTOS

Changing communication channel and RF Power

2008-01-17T01:34:00.000-08:00

To change default communication channel and RF Power you can either:
1) edit opt/tinyos-1.x/tos/lib/CC2420Radio/CC2420Const.h
CC2420_DEF_CHANNEL 11 (this is default value)
CC2420_DEF_RFPOWER 0x1f (31, maximum, if you for example want to test multihop routing easiest way is to make RFPOWER smaller)

2) add line in Makefile
CC2420_DEF_CHANNEL = 11
CC2420_DEF_RFPOWER= 0x1f

3) change it in program by colling function from CC2420Control interface, called:
SetRFPower(uint8_t power);

TinyOS little help

2008-01-16T09:51:00.000-08:00

Last 2 months I was actively working in TinyOS, and since there's no better place than internet to put solutions to problems which most likely you will forget in near future, I will write here some little things about TinyOS.

In general, that was the main idea of this blog.
Quite recently I started with Linux, which have as usual, a lot of difficulties with drivers; you find a number of solutions which maybe one or maybe none is working.

Yes this is also public cause I support idea of helping people with similar problems over internet.
That is just my gratitude for all those nice people who helped me simply by posting their solutions on forums and other public places.

Raising Elephants Is So Utterly Boring

2007-10-12T09:24:00.000-07:00

Taken from http://en.wikipedia.org/wiki/Magic_SysRq_key
"Raising Elephants Is So Utterly Boring" is a mnemonic device for remembering a keystroke sequence that should be used as an alternative to hitting the power button if a Linux system should ever freeze and need to be rebooted.
Alt + SysRq + R – takes the keyboard out of raw mode.
Alt + SysRq + E – terminates all processes (except init).
Alt + SysRq + I – kills all processes (except init).
Alt + SysRq + S – synchronizes the disk.
Alt + SysRq + U – remounts all filesystems read-only.
Alt + SysRq + B – reboots the machine.
Or it can be remembered as "BUSIER" in reverse.
"Raising Skinny Elephants Is Utterly Boring" is an alternative mnemonic for the same series of keystrokes, though changing the position of the disk synchronization to before terminating and killing all processes.
Regardless of which of the above hotkey sequences are chosen, they should be entered in slow succession, giving the system a chance to complete earlier steps before moving on to subsequent ones. Typing the sequence slowly may allow the system to safely terminate most or all processes before the more drastic kill command is invoked. Also, to minimize the chance of data corruption, it is a good idea to wait between the disk synchronization command and the unmount and finally the reboot command.
An alternative to issuing the REISUB/RSEIUB keystrokes is to just press Alt + SysRq + R, followed by Ctrl + Alt + Del. This is the equivalent of issuing a shutdown now command at a root console; it does take a short while for the system to shut down after the Ctrl + Alt + Del keystroke. However, not all Linux systems support this easier method.

Special thanks to my sister :)

starting program from terminal in background

2007-10-12T09:10:00.000-07:00

So, if you want to start the program and to use terminal afterwards, you just need to put "&" character at the end of the line
so, for example, if you just want to call skype, then you write skype&

It is simple thing, but sometimes one just forget this as a option :)

Embedded Font Problems with PDF files

2007-10-12T09:05:00.000-07:00

Some of you may have encountered some problem of embedded fonts with PDF
files. All fonts are embedded with the following command (Linux):

ps2pdf14 -dPDFSETTINGS=/prepress -dEmbedAllFonts=true file.ps file.pdf

This is done thanks to my colleague, Alex :)

RPMs

2007-10-11T09:11:00.000-07:00

This can be useful for those who had problems installing programs in openSUSE 10.2 (in my case, YasT is somehow crashing very often).
To install rpm package:
rpm -ivh packagename
To upgrade the package:
rpm -Uvh packagename
To remove the package:
rpm -e packagename

If you not sure that your package is installed, there is a way to see it:
rpm -qa packagename
There can be problems to remember full name of the package since it is having all those version numbers etc.etc. so instead of writing out whole name, you can do next command:
rpm -qa | grep SomeKeywordOfWantedPackage

Cheers!

How to merge multiple pdf files into one

2007-10-01T13:58:00.001-07:00

Linux command:
gs -dNOPAUSE -sDEVICE=pdfwrite -sOUTPUTFILE=Merged.pdf -dBATCH *.pdf

how to install source programs in linux

2007-09-12T04:19:00.000-07:00

How often does it happen to you to download a new program which happen not to be any kind of debian package or something similar that you just need to use option install.

Beforehand, look for README text which will probably tell you how to install the program

Often for those, source code applications there are couple of steps to do in order to install them.
1. open terminal window (I use yakuake, in which u can open terminal just by pressing F12)
2. go to directory of your new, just downloaded application
3. run ./configure command - it looks if your system is ready to install application. It is checking for packages it needs to get its installed (newly downloaded application)
4. Look for comments at the end. If there is some comment like, error: 'libxyz' is not found, than you have to look for package that contains this library. I use adept-manager to search for those, and google if I fail to find it there.
5. when you finally install all packages needed, you proceed to next step
6. run make command
7. run make install command
8. finito, last two commands should run smoothly, if there are still some problems, consult google with keyword as your error text.

Yakuake

2007-09-11T15:48:00.000-07:00

very cool console which starts when u press F12.
alt-f2 and then write yakuake

To put translate absolute link into relative links

2007-09-07T08:04:00.000-07:00

Search for: http://((.*)/)*(.*)"
Replace with: \3"

Useful when you have downloaded all file from particular page, but you need this webpage for navigation through files.

Download a list of files (list of their links)

2007-09-07T07:25:00.000-07:00

If you have list of files you need to download, there is a way to do that automatically.
so, assuming every line is starting with http:... in any kind of text editor you replace option to replace every "http" with "wget -c -t5 -l1 http".
Then Save the list-file as a download.sh.
When you do that, then go to terminal/console window, type chmod 777 download.sh
and then ./download.sh

It then downloads everything from the list into current folder.

HTTPS website download

2007-09-03T05:49:00.000-07:00

linux command
wget -r --http-user=USERNAME --http-password=PASSWORD https://www.SOMEPAGE.com

A lot of download managers and windows freeware website downloaders claim that they can download from https website, but somehow they always fail to login to page.