function rollo(name,over)
{
	//alert(name);
	var name = arguments[0];
	var over = arguments[1];
	var img_name;
	

	if (arguments[2]) {
		img_name = arguments[2];
	} else {
		img_name = arguments[0];
	}

	
		if(over)
			window.document.images[img_name].src = "images/" + name +
"_on.gif";
		else
			window.document.images[img_name].src =  "images/" + name +
".gif";

}