I wanted to comment on @Ionica Bizau, but I don't have enough reputation.
To give a reply to your question about javascript code:
What you need to do is get the parent's element height (minus any elements that take up space) and apply that to the child elements.
function wrapperHeight(){
var height = $(window).outerHeight() - $('#header').outerHeight(true);
$('.wrapper').css({"max-height":height+"px"});
}
Note
window could be replaced by ".container" if that one has no floated children or has a fix to get the correct height calculated. This solution uses jQuery.