hello all

I'm busy building my own website and I'm almost done.
However, when I tried the page with other bowsers, I couldn't scroll down.http://webpages.avans.nl/acue-gast01...ofdwerken.html
i won't bother you with the whole code, but if you wan't I can post it obviously.
Hopefully you guys can help me, cause I and my teacher (typical) have run out of ideas.