var menu = function(){
	var t = 15, z = 50, s = 6, a;
	function sl(c, f){
		var h = c.offsetHeight;
		if ((h <= 0 && f != 1) || (h >= c.mh && f == 1)) {
			if (f == 1) {
				c.style.filter = '';
				c.style.opacity = 1;
				c.style.overflow = 'visible';
			}
			clearInterval(c.t);
			return
		}
		var d = (f == 1) ? Math.ceil((c.mh - h) / s) : Math.ceil(h / s), o = h / c.mh;
		c.style.opacity = o;
		c.style.filter = 'alpha(opacity=' + (o * 100) + ')';
		c.style.height = h + (d * f) + 'px';
	};
	function dd(n){
		this.h = [];//存取有子菜单的项目
		this.c = [];//存取子菜单
	};
	dd.prototype = {
		init: function(p, c){
			a = c;
			var that = this;
			var w = document.getElementById(p), s = w.getElementsByTagName('ul'), l = s.length/*二级菜单的个数*/, i = 0;
			for (i; i < l; i++) {
				var h = s[i].parentNode;
				this.h[i] = h;
				this.c[i] = s[i];
				/*
				 * 重点就在这里，一点JS的语法技巧，通过闭包来实现对i（索引的传递）
				 * 然后就是Javascript里比较奇怪的一点，必须在内部的函数之外声明that=this
				 * 这样对象的作用域才可以保持，很奇怪，但是很有效
				*/ 
				h.onmouseover = function(index){
					return function(){
						that.st(index, true);
					}
				}(i);
				h.onmouseout = function(index){
					return function(){
						that.st(index, false);
					}
				}(i);
			}
		},
		st: function(x, f){
			var c = this.c[x], h = this.h[x], p = h.getElementsByTagName('a')[0];
			if (c.t) {
				clearInterval(c.t);
			}
			c.style['overflow'] = 'hidden';
			if (f) {
				p.className += ' ' + a;
				if (!c.mh) {
					c.style.display = 'block';
					c.style.height = '';
					c.mh = c.offsetHeight;
					c.style.height = 0;
				}
				if (c.mh == c.offsetHeight) {
					c.style.overflow = 'visible';
				}
				else {
					c.style.zIndex = z;
					z++;
					c.t = setInterval(function(){
						sl(c, 1)
					}, t);
				}
			}
			else {
				p.className = p.className.replace(a, '');
				c.t = setInterval(function(){
					sl(c, -1)
				}, t);
			}
		}
	};
	return {
		dd: dd
	};
}();
function MM_swapImgRestore() { //v3.0
  var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}
function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}

function MM_findObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}

function MM_swapImage() { //v3.0
  var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
   if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}