How to keep the top div height fixed and bottom div height in %age

[mikejcon]

I have created two divs in a page one is header and other is the content \[code\] <div id="main"> <div id="header"> </div> <div id="content"> </div> </div>\[/code\]And the style is \[code\]<style>#main{height:100%;}#header{height:100px}#content{height:???? // to fit the content 100% on any kind of screen }</style>\[/code\]I want to adjust the content according to the screen. screen height can be 100px and it might be 2000px. How I can do it with css. I do not want white space at the bottom or to scroll the page