Scale to the bottom of the browser and form help

Hi I’m learning CSS and I have an understanding of HTML and need some help with a site I’m trying to develop.
The CSS file is if you want to look at it.

There’s still a few layout problems. I’m building it on a Mac so PC browsers have more probs than Mac…Anyway, I want the bottom of the green on the left to scale all the way down to and move with the bottom of the browser window. Is this possible? If so can you tell me how I do it?

Also can someone tell me how to create form that users can fill out and email to self help services?

Thanks for your help.