function scrollDoor() {
}
scrollDoor.prototype = {
      sd: function (menus, divs, openClass, closeClass) {
            var _this = this;
            if (menus.length != divs.length) {
                  alert("菜单层数量和内容层数量不一样!");
                  return false;
            }
            for (var i = 0; i < menus.length; i++) {
                  _this.$(menus[i]).value = i;
                  _this.$(menus[i]).onmouseover = function () {

                        for (var j = 0; j < menus.length; j++) {
                              _this.$(menus[j]).className = closeClass;
                              _this.$(divs[j]).style.display = "none";
                        }
                        _this.$(menus[this.value]).className = openClass;
                        _this.$(divs[this.value]).style.display = "block";
                  }
            }
      },
      $: function (oid) {
            if (typeof (oid) == "string")
                  return document.getElementById(oid);
            return oid;
      }
}
//返回顶部jquery
$(document).ready(function () {
      if (document.getElementById('return_top') != null) {
            var s = $('#return_top').offset().top;
            $(window).scroll(function () { $("#return_top").animate({ top: $(window).scrollTop() + s + "px" }, { queue: false, duration: 500 }); });
            $('#shang').click(function () { $('html,body').animate({ scrollTop: '0px' }, 600);return false });
      }
});