Can't find an error on my site

[paldo]

I don't know why on my site
http://paolinet.info/aude/aude/inscription.html
between <div id="container4"><img src="top.jpg" width="900" height="111" /></div>
and <div id="container3"> there is a big white gap. How can I get reed of it?

Thanks for your help.

[paldo]

Thanks, I found the error in my CSS.