Trying to copy text to the clipboard in Firefox

Question

Briefly : Trying to copy text to the clipboard in Firefox
 
In details :
I am developing a web application which requires to copy the selected text of a text area to be copied to the clipboard on click(or any events). Everything is working okay, except the functionality(Javascript code) that copies the content of the Text-area to the clipboard.
 
This is working correctly in IE browsers. But my issue is with Firefox. I tried all options, It is primarily a security/restriction in Firefox that doesn't allow copying to Clipboard look at their security http://kb.mozillazine.org/Granting_JavaScript_access_to_the_clipboard[^].
 
Anyone of you have done this before? Any idea?