// JavaScript Document

//导航固定

	var FixedBox=function(el){

		this.element=el;

		this.BoxY=getXY(this.element).y;

	}

	FixedBox.prototype={

		setCss:function(){

			var windowST=(document.compatMode && document.compatMode!="CSS1Compat")? document.body.scrollTop:document.documentElement.scrollTop||window.pageYOffset;

			if(windowST>this.BoxY){

				this.element.style.cssText=" position:fixed; top:0px; width:100%; z-index:100; left:0px; padding-bottom:0px;  margin-top:0;  opacity:0.9; filter:alpha(opacity=90); padding:0; ";

			}else{

				this.element.style.cssText="";

			}

		}

	};

	//添加事件

	function addEvent(elm, evType, fn, useCapture) {

		if (elm.addEventListener) {

			elm.addEventListener(evType, fn, useCapture);

		return true;

		}else if (elm.attachEvent) {

			var r = elm.attachEvent('on' + evType, fn);

			return r;

		}

		else {

			elm['on' + evType] = fn;

		}

	}

	//获取元素的XY坐标；

	function getXY(el) {

        return document.documentElement.getBoundingClientRect && (function() {//取元素坐标，如元素或其上层元素设置position relative

            var pos = el.getBoundingClientRect();

            return { x: pos.left + document.documentElement.scrollLeft, y: pos.top + document.documentElement.scrollTop };

        })() || (function() {

            var _x = 0, _y = 0;

            do {

                _x += el.offsetLeft;

                _y += el.offsetTop;

            } while (el = el.offsetParent);

            return { x: _x, y: _y };

        })();

    }

	//实例化；

	var divA=new FixedBox(document.getElementById("deanhfbottom"));

   	addEvent(window,"scroll",function(){

		divA.setCss();

	});

	