if (mtDropDown.isSupported()) {

		var ms = new mtDropDownSet(mtDropDown.direction.down, 0, 0, mtDropDown.reference.bottomLeft);
		var menu1 = ms.addMenu(document.getElementById("menu1"));
		menu1.addItem("  防火板系列", "product.asp?Catalog=4");
		menu1.addItem("  钢地板板系列", "Product1.asp?Catalog=3");
		mtDropDown.renderAll();
	}