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

var	menu4	=	ms.addMenu(document.getElementById("mainmenu4"));
menu4.addItem("四大产业",	"/userlist/lzjjxh/text-1003.html","");
menu4.addItem("四大园区",	"/userlist/lzjjxh/text-1004.html","");
menu4.addItem("四大通道",	"/userlist/lzjjxh/text-1005.html","");
menu4.addItem("四大中心",	"/userlist/lzjjxh/text-1006.html","");

			mtDropDown.renderAll();
		}
		//初始菜单
		window.onload = init;