function getViewPort(){
	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
	}
	 
	return new Array(viewportwidth,viewportheight);
}

function fixMenuBg(){
	var menu =document.getElementById('menu_info');
	var viewPortHeight = getViewPort()[1];
	var mainHeight = document.getElementById('mainSpacer').offsetHeight;
	if(mainHeight < viewPortHeight){
		menu.style.height=viewPortHeight+"px";
	} else {
		menu.style.height=mainHeight+"px";
	}
}