/* get the window height */
var viewportwidth;
var viewportheight;
  
// the more standards compliant browsers (mozilla/netscape/opera/IE7) use window.innerWidth and window.innerHeight
  
if (typeof window.innerWidth != 'undefined')
{
	viewportwidth = window.innerWidth,
	viewportheight = window.innerHeight
}
  
// IE6 in standards compliant mode (i.e. with a valid doctype as the first line in the document)
 
else if (typeof document.documentElement != 'undefined'
	&& typeof document.documentElement.clientWidth !=
	'undefined' && document.documentElement.clientWidth != 0)
{
	viewportwidth = document.documentElement.clientWidth,
	viewportheight = document.documentElement.clientHeight
}
  
// older versions of IE
  
else
{
	viewportwidth = document.getElementsByTagName('body')[0].clientWidth,
	viewportheight = document.getElementsByTagName('body')[0].clientHeight
}

/* set the main content min-height to fill the screen unless it is less than 500, then choose 500*/
function min_height() {
	var new_min = viewportheight-200-document.getElementById("colophon").offsetHeight;
	if (new_min < 500) {
		new_min = 500;
	}
	document.getElementById("main").style.minHeight=(new_min)+"px";
}