var side

function flip(element, frontImage, backImage)
{
	if (side == undefined)
	{
		side = "front";
	}

	if (side == "front")
	{
		var object = "document." + element + ".src = '" + backImage + "';";
		eval(object);
		side = "back";
	}
	else
	{
		var object = "document." + element + ".src = '" + frontImage + "';";
		eval(object);
		side = "front";
	}
}