problems in IE6 and IE7

I've got my site displaying correctly in Safari, Firefox, Chrome, IE8, but in IE6 and IE7, it looks really messed up. The main problem is the horizontal navigation bar is displaying vertically. If anyone would like to take a look at the code, here is the link to the site:
SlimeKids - School Library Media Kids

problem solved

Apparently, all I had to do was set a width long enough for the #nav to make it horizontal in IE7.