Adding video to website confusion

hi everyone.

my website is:

the video at the main page is seems ok in chrome,opera and safari well.but in ff and ie not working.i know about ie is not accepting video tag.
the video begins automatically,when page is loaded.when i click one of buttons at the bottom of page,the video that is working will paused.i wrote a script for this but while this script is active,ff is not open video.when i move the script that i mentioned into the head tag,the video is begin to work in ff.i do not understand why.
does anyone help me to solve my brain confuse?

i also wondered how can i embed video for ie.

besides can i change the images of video controls programmatically?