Hi guys,
I am having problem with this everytime. And it took me so many hours to fix it and I still couldn't figure out how.

I have a left column id (css) with all the navigations. And the right is the content. But everytime when my content gets longer, the left column will have white space below it. I tried height: auto. But still won't help.

You either have to set both divs to 100% height (see stickies for how), or you'll have to use the faux-columns method to fake it.
http://css-discuss.incutio.com/?page=AnyColumnLongest

Yeah. ok thank you so much.
I managed to solve it!!

But mine is not so complex.got abit of hint from the tutorials is that they play around with backgrounds. I placed a bg behind the left and right column but the div ends after the footer. and it works !

Thank you again for the effort and time.