if (mtDropDown.isSupported()) {

// x轴：-10；y轴：-6 
		var ms = new mtDropDownSet(mtDropDown.direction.down, 0, 12  , mtDropDown.reference.bottomLeft);

		var menu1 = ms.addMenu(document.getElementById("menu1"));
		menu1.addItem("概况", "about.html");
		menu1.addItem("交通位置", "about_jtwz.html");
		


 
		var menu2 = ms.addMenu(document.getElementById("menu2"));


		var menu3 = ms.addMenu(document.getElementById("menu3"));
		
		

		var menu4 = ms.addMenu(document.getElementById("menu4"));


		var menu5 = ms.addMenu(document.getElementById("menu5"));

		
		var menu6 = ms.addMenu(document.getElementById("menu6"));

		
		var menu7 = ms.addMenu(document.getElementById("menu7"));


		mtDropDown.renderAll();
	}