Download Video From Youtube Using Firefox

i think that it's not that great creation but some of us needs it and they don't know how to do it, so i hope it will be useful

i think that doing it using google is easier than memorizing the web site but here you can click the link below

www.downloadhelper.net/install.php

then you can choose the "video download helper" add-on by clicking install button beside it

after clicking the "download" , download bar will appear. it will take no time, and after finishing installation window with a timer will appear, after the timer finishes it will enable the install button, then you will have to restart the program- you can choose to restart it later -.
after restarting you are ready to go

when you start the program after finishing you will notice the add-on logo next to the url textbox
so when you enter some video page on www.youtube.com the logo will be colored and enabled and a small arrow will appear,when you click the arrow download options will appear and you can choose one by the resolution you want

hope it works well with you