// version 1.0
	// takes image name (as passed by NAME attribute of IMG)
	// appends either a 2 (on) or 1 (off) to the imagename
	
	function rollOn(imageName) {
		var imageNameOn = "images/" + imageName + "2.gif";
		document.images[imageName].src = imageNameOn;
	}

	function rollOff(imageName) {
		var imageNameOff = "images/" + imageName + "1.gif";
		document.images[imageName].src = imageNameOff;
	}