一个支持二级子菜单的 Javascript 动态下拉菜单[JS][7Z]

mtDropDown.spacerGif = "js/list.gif";
mtDropDown.dingbatOn = "js/more_list.gif";
mtDropDown.dingbatOff = "js/more.gif";
mtDropDown.dingbatSize = 14;
mtDropDown.menuPadding = 5;    //下拉菜单中的padding
mtDropDown.itemPadding = 4;    //下拉菜单之间的行间距
mtDropDown.shadowSize = 2;    //应该是下拉菜单下面和右面的定位
mtDropDown.shadowOffset = 3;
mtDropDown.shadowColor = "#E3E3E3";    //下拉菜单底框的颜色
mtDropDown.shadowPng = "";
mtDropDown.backgroundColor = "#F3F3F3"; //下拉菜单的背景颜色
mtDropDown.backgroundPng = "";
mtDropDown.hideDelay = 200;
mtDropDown.slideTime = 300;    //下拉菜单出现和消失时的快慢程度
mtDropDown.reference = {topLeft:1,topRight:2,bottomLeft:3,bottomRight:4};
mtDropDown.direction = {down:1,right:2};
mtDropDown.registry = [];
mtDropDown._maxZ = 100;
mtDropDown.isSupported = function() {
if (typeof mtDropDown.isSupported.r == "boolean")
return mtDropDown.isSupported.r;
var ua = navigator.userAgent.toLowerCase();
var an = navigator.appName;
var r = false;
if (ua.indexOf("gecko") > -1) r = true;
else if (an == "Microsoft Internet Explorer") {
if (document.getElementById) r = true;
}
mtDropDown.isSupported.r = r;
return r;
}
mtDropDown.initialize = function() {
for (var i = 0, menu = null; menu = this.registry[i]; i++) {
menu.initialize();
}
}
mtDropDown.renderAll = function() {
var aMenuHtml = [];
for (var i = 0, menu = null; menu = this.registry[i]; i++) {
aMenuHtml[i] = menu.toString();
}
document.write(aMenuHtml.join(""));
}
function mtDropDown(oActuator, iDirection, iLeft, iTop, iReferencePoint, parentMenuSet) {
this.addItem = addItem;
this.addMenu = addMenu;
this.toString = toString;
this.initialize = initialize;
this.isOpen = false;
this.show = show;
this.hide = hide;
this.items = [];
this.onactivate = new Function();
this.ondeactivate = new Function();
this.onmouseover = new Function();
this.onqueue = new Function();
this.index = mtDropDown.registry.length;
mtDropDown.registry[this.index] = this;
var id = "mtDropDown" + this.index;
var contentHeight = null;
var contentWidth = null;
var childMenuSet = null;
var animating = false;
var childMenus = [];
var slideAccel = -1;
var elmCache = null;
var ready = false;
var _this = this;
var a = null;
var pos = iDirection == mtDropDown.direction.down ? "top" : "left";
var dim = null;
[以下略]