ajax loading error in IE7 and opera [newbie][Solved]

ajax loading error in IE7 and opera [newbie][Solved]

Hello,
I'm working on my site and i'm implementing some jquery stuff. Everything is ok with firefox but with IE and opera i get errors and my code isn't working at all.

You can see it there : http://homemade.artefakt.be

I'm totally new to this, so tell me what i'm doing wrong

Thanks,

ubik