setting DIV heights to 100% not working?

I posted a question on here a couple days ago and you guys were really helpful, so I thought I'd throw another one at you.

i'm working on a website and want the heights of the of the divs to automatically adjust according to the content, instead of me going in and changing the div height manually. i've set the div heights to 100% but there is still a lot of white space at the bottom of them or they hang over the footer of the page. How do I make them all size up nicely and have the footer follow beneath it, instead of staying put.


here is the site:
www.chrissybdesign.com/exporttradebrokers

the pages I'm having trouble with specifically are:
http://chrissybdesign.com/exporttradebrokers/whyexport.html
http://chrissybdesign.com/exporttradebrokers/businessmarketing.html
http://chrissybdesign.com/exporttradebrokers/getStarted.html

what am i doing wrong? thanks in advance

When you set a div to 100% height, it means to use 100% of the available vertical space, divs usually do adjust their height according to what is inside them without explicitly declaring it, but you can try height:auto;.