function RollOverButtons ()
{	
	var imgOn = new Array();
	var imgOff = new Array();
	
	this.LoadImage = LoadImage;
	this.HoverOn = HoverOn;
	this.HoverOff = HoverOff;
	
	function LoadImage(imgId, url_on, url_off)
	{	
		if (document.images)
		{
			imgOn[imgId] = new Image();
			imgOn[imgId].src = url_on;
			
			imgOff[imgId] = new Image();
			imgOff[imgId].src = url_off;
		}
	}
	
	function HoverOn(imgId)
	{
		if (document.images)
		{
			document.getElementById(imgId).src = imgOn[imgId].src;
		}
	}
	
	function HoverOff(imgId)
	{
		if (document.images)
		{
			document.getElementById(imgId).src = imgOff[imgId].src;
		}
	}
}