function adjust_footer()
{
	var center = document.getElementById("middle");
	var right = document.getElementById("rightcolumn");
	var left = document.getElementById("leftcolumn");
	var center_height = center.offsetHeight + center.offsetTop;	
	var left_height = left.offsetHeight + left.offsetTop;	
	var right_height = right.offsetHeight + right.offsetTop;	
	
	var max_height = left_height > center_height ? left_height : center_height;
	max_height = max_height > right_height ? max_height : right_height;
	document.getElementById("body").style.height= max_height;
}