if (mtDropDown.isSupported()) {
  var ms = new mtDropDownSet(mtDropDown.direction.down, 0, 0, mtDropDown.reference.bottomLeft);
  var menu1 = ms.addMenu(document.getElementById("menu1"));
  menu1.addItem(" 公司简介 ", "/classinfo.aspx?classid=7");
  menu1.addItem(" 公司环境 ", "/classinfo.aspx?classid=8");
  menu1.addItem(" 公司历程 ", "/classinfo.aspx?classid=9");
  menu1.addItem(" 企业文化 ", "/classinfo.aspx?classid=10");
  menu1.addItem(" 组织机构 ", "/classinfo.aspx?classid=11");
  menu1.addItem(" 荣誉证书 ", "/classinfo.aspx?classid=12");
  menu1.addItem(" 产品认证证书 ", "/classinfo.aspx?classid=61");

  var menu2 = ms.addMenu(document.getElementById("menu2"));
  menu2.addItem(" YWF系列产品概述 ", "http://www.wgmotor.com/products.aspx?deep=1&classid=163");
  menu2.addItem(" YWF系列外转子轴流风机 ", "http://www.wgmotor.com/products.aspx?deep=1&classid=159");
  menu2.addItem(" YWF系列离心风机 ", "http://www.wgmotor.com/products.aspx?deep=1&classid=158");
  menu2.addItem(" YWF系列外转子电机 ", "http://www.wgmotor.com/products.aspx?deep=1&classid=157");
  menu2.addItem(" YZF系列产品概述 ", "http://www.wgmotor.com/products.aspx?deep=1&classid=209");
  menu2.addItem(" YZF系列罩极电机 ", "http://www.wgmotor.com/products.aspx?deep=1&classid=156");
  menu2.addItem(" ECM系列电子整流无刷电机 ", "http://www.wgmotor.com/products.aspx?deep=1&classid=153");
  menu2.addItem(" YCF系列电机 ", "http://www.wgmotor.com/products.aspx?deep=1&classid=154");
  menu2.addItem(" YZF30罩极电机/YGF贯流风机  ", "http://www.wgmotor.com/products.aspx?deep=1&classid=155");
  menu2.addItem(" YJF系列罩极电机 ", "http://www.wgmotor.com/products.aspx?deep=1&classid=151");
  
  var menu3 = ms.addMenu(document.getElementById("menu3"));
  menu3.addItem(" 公司动态 ", "/news.aspx?classid=15");
  menu3.addItem(" 学习园地 ", "/news.aspx?deep=1&classid=16");

  var menu4 = ms.addMenu(document.getElementById("menu4"));
  menu4.addItem(" 下载专区 ", "/news.aspx?deep=1&classid=22");
  menu4.addItem(" 服务网络 ", "/classinfo.aspx?classid=23");
  menu4.addItem(" 常见问题 ", "/news.aspx?deep=1&classid=24");
  menu4.addItem(" 用户反馈 ", "/server.aspx?deep=1&classid=25");

  mtDropDown.renderAll();
 }