function $(id)
{ 
	var obj = document.getElementById(id);
	return obj;
}

function Querystring() 
{ 
	this.params = new Object();
	this.get = Querystring_get;
	
	//Get the querystring from the URL...
	qs=location.search.substring(1, location.search.length); 
	if (qs.length == 0) { return; }

	// Make '+' a whitespace
	qs = qs.replace(/\+/g, ' ');
	var args = qs.split('&') ;
	
	// split out each name/value pair
	for (var i=0;i<args.length;i++) 
	{
		var value;
		var pair = args[i].split('=');
		var name = unescape(pair[0]);

		if (pair.length == 2)
			value = unescape(pair[1]);
		else
			value = name;
		
		this.params[name] = value;
	}
}

function Querystring_get(key, val) 
{
	//in case val is undefined as opposed to null...
	if (val == null) val = null;
	
	var value = this.params[key];
	if (value==null) { value=val; }
	
	return value;
}

function isMCInstalled()
{
	if(navigator.userAgent.indexOf("Media Center PC") > -1)
	{	return true; } 
	else
	{ return false; }
}

function isVista()
{
	if(navigator.userAgent.indexOf("Windows NT 6.0") > -1)
	{ return true; }
	else
	{ return false; }
}

function rollOver(id)
{
	if ($(id).src != null)
	{
		var ext = $(id).src.slice(-4).toLowerCase(); //file extension
	}
	
	if ($(id).outerHTML == null || ext == '.gif')
	{	
		var file = $(id).src;
		$(id).src = file.slice(0,-4) + "_on" + ext;
	} 
	else
	{
		if($(id).outerHTML.indexOf('_on.png') == -1)
		{																					 
			$(id).outerHTML = $(id).outerHTML.replace('.png', '_on.png');
		}
	}
}

function rollOut(id)
{
	if ($(id).src != null)
	{
		var ext = $(id).src.slice(-4).toLowerCase(); //file extension
	}
	
	if ($(id).outerHTML == null || ext == '.gif')
	{	
		var file = $(id).src;
		$(id).src = file.slice(0,-7) + ext;
	} 
	else
	{
		$(id).outerHTML = $(id).outerHTML.replace('_on.png', '.png');
	}
}