页面浮动窗口效果实现

<style type="text/css">
 #msg_win{border:1px solid #316DC9;background:#EAEAEA;width:145px;position:absolute;right:0;font-size:12px;font-

 family:Arial;margin:0px;display:none;overflow:hidden;z-index:99;}
 #msg_win .icos{position:absolute;top:2px;*top:0px;right:2px;z-index:9;}
 .icos a{float:left;color:#316DC9;margin:1px;text-align:center;font-weight:bold;width:14px;height:22px;line-

 height:22px;padding:1px;text-decoration:none;font-family:webdings;}
 .icos a:hover{color:#316DC9;}
 #msg_title{background:#FFFFFF;border-bottom:1px solid #316DC9;border-top:1px solid #FFF;border-left:1px solid 

 #FFF;color:#316DC9;height:25px;line-height:25px;text-indent:5px;}
 #msg_content{margin:0px;width:145px;height:120px;overflow:hidden;}
</style>
<div id="msg_win" style="display:block;top:490px;visibility:visible;opacity:1;">
 <div class="icos"><a id="msg_min" title="最小化" href="javascript:void 0" _fcksavedurl="javascript:void 0">_</a><a id="msg_close" 

 title="关闭" href="javascript:void 0" _fcksavedurl="javascript:void 0">×</a></div>
 <div id="msg_title">学习平台</div>
 <div id="msg_content">

  <a href="www.sina.com.cn" target="_blank">
  <img src="http://www.sina.com.cn" 
  width="145" height="120" border="0"/></a>
  <!--图片地址-->
 </div>
</div>
<script language="javascript">
 var Message={
 set: function() {//最小化与恢复状态切换
 var set=this.minbtn.status == 1?[0,1,'block',this.char[0],'最小化']:[1,0,'none',this.char[1],'恢复'];
 this.minbtn.status=set[0];
 this.win.style.borderBottomWidth=set[1];
 this.content.style.display =set[2];
 this.minbtn.innerHTML =set[3]
 this.minbtn.title = set[4];
 this.win.style.top = this.getY().top;
 },
 close: function() {//关闭
 this.win.style.display = 'none';
 window.onscroll = null;
 },
 setOpacity: function(x) {//设置透明度
 var v = x >= 100 ? '': 'Alpha(opacity=' + x + ')';
 this.win.style.visibility = x<=0?'hidden':'visible';//IE有绝对或相对定位内容不随父透明度变化的bug
 this.win.style.filter = v;
 this.win.style.opacity = x / 100;
 },
 show: function() {//渐显
 clearInterval(this.timer2);
 var me = this,fx = this.fx(0, 100, 0.1),t = 0;
 this.timer2 = setInterval(function() {
 t = fx();
 me.setOpacity(t[0]);
 if (t[1] == 0) {clearInterval(me.timer2) }
 },10);
 },
 fx: function(a, b, c) {//缓冲计算
 var cMath = Math[(a - b) > 0 ? "floor": "ceil"],c = c || 0.1;
 return function() {return [a += cMath((b - a) * c), a - b]}
 },
 getY: function() {//计算移动坐标
 var d = document,b = document.body, e = document.documentElement;
 var s = Math.max(b.scrollTop, e.scrollTop);
 var h = /BackCompat/i.test(document.compatMode)?b.clientHeight:e.clientHeight;
 var h2 = this.win.offsetHeight;
 return {foot: s + h + h2 + 2+'px',top: s + h - h2 - 2+'px'}
 },
 moveTo: function(y) {//移动动画
 clearInterval(this.timer);
 var me = this,a = parseInt(this.win.style.top)||0;
 var fx = this.fx(a, parseInt(y));
 var t = 0 ;
 this.timer = setInterval(function() {
 t = fx();
 me.win.style.top = t[0]+'px';
 if (t[1] == 0) {
 clearInterval(me.timer);
 me.bind();
 }
 },10);
 },
 bind:function (){//绑定窗口滚动条与大小变化事件
 var me=this,st,rt;
 window.onscroll = function() {
 clearTimeout(st);
 clearTimeout(me.timer2);
 me.setOpacity(0);
 st = setTimeout(function() {
 me.win.style.top = me.getY().top;
 me.show();
 },600);
 };
 window.onresize = function (){
 clearTimeout(rt);
 rt = setTimeout(function() {me.win.style.top = me.getY().top},100);
 }
 },
 init: function() {//创建HTML
 function $(id) {return document.getElementById(id)};
 this.win=$('msg_win');
 var set={minbtn: 'msg_min',closebtn: 'msg_close',title: 'msg_title',content: 'msg_content'};
 for (var Id in set) {this[Id] = $(set[Id])};
 var me = this;
 this.minbtn.onclick = function() {me.set();this.blur()};
 this.closebtn.onclick = function() {me.close()};
 this.char=navigator.userAgent.toLowerCase().indexOf('firefox')+1?['_','::','×']:['0','2','r'];//FF不支持webdings字体
 this.minbtn.innerHTML=this.char[0];
 this.closebtn.innerHTML=this.char[2];
 setTimeout(function() {//初始化最先位置
 me.win.style.display = 'block';
 me.win.style.top = me.getY().foot;
 me.moveTo(me.getY().top);
 },0);
 return this;
 }
 };
 Message.init();
</script>