if (mtDropDown.isSupported()) 
		{
			var ms = new mtDropDownSet(mtDropDown.direction.down, 0, 0, mtDropDown.reference.bottomLeft);

var	menu2	=	ms.addMenu(document.getElementById("mainmenu2"));
menu2.addItem("经营理念",	"gsln.php","_blank");
menu2.addItem("公司地图",	"gsmap.php","_blank");

			mtDropDown.renderAll();
		}
		//��ʼ�˵�
		window.onload = init;