CSS Middle Div and Footer Div Problem

Hello. I have no idea how to fix my problem, and I am hoping someone would be kind enough to help me.

I have set up my template to have a wrapper div with a top, middle, and bottom div inside.

What I need to do is have the footer (bottom div called (wrapper_bottom) move down when the content in the middle div (wrapper_middle) has more content added. Currently, when content is added to the middle div (wrapper_middle), it pushes the bottom div content out of the way. Maybe I have the divs set up wrong or maybe have them listed in the html file incorrectly?

I have uploaded a zip file of my files here:
www.dpegues.com/site_help.zip

It is also attached to this thread posting.

It contains my site images, the template in the folder called Templates, and the css file.

Thank you everyone.

All you need to keep the wrapper_bottom from getting over lapped or moved to the side is "clear:both;" applied to the wrapper_bottom div.

This creates a new problem, however, that your wrapper_middle and wrapper_middle_main div's (and applied graphics) don't enlarge with the extended pad_md div. Considering your know how, I trust you know how to fix that. ;)

-SDPETERSEN
Mohican Web Ware