function DoRollover(ImgRef){
	var ImgStem = ImgRef.src.substring(0,ImgRef.src.lastIndexOf('.'));
	var ImgType = ImgRef.src.substring(ImgRef.src.lastIndexOf('.'),ImgRef.src.length);
	ImgRef.src = ImgStem + '_Ovr' + ImgType;
}

function DoRollout(ImgRef){
	var ImgStem = ImgRef.src.substring(0,ImgRef.src.lastIndexOf('.')-4);
	var ImgType = ImgRef.src.substring(ImgRef.src.lastIndexOf('.'),ImgRef.src.length);
	ImgRef.src = ImgStem + ImgType;
}