<style type="text/css">

<!--
/*** banner样式 ***/
#banner{width:475px; height:300px; float:left; display: inline; position:relative; }
#banner .Limg{position:relative;}
#banner .Limg li{position:absolute;top:0;left:0;background:#fff;}
#banner .Limg li p{line-height:25px; font-size:14px; padding-left:15px;}
#banner .Nubbt{position:absolute;z-index:9; bottom:10px;right:10px;}
#banner .Nubbt span{ float:right; color:#fff; padding:0px 5px; height:16px; line-height:16px; font-style:normal; margin-left:4px; border:#cecfd3 1px solid; background:#fff; color:#333; cursor:pointer; text-align:center;}
#banner .Nubbt span.on{ display:block; background:#9f0000; border:#880001 1px solid; color:#fff; }
-->
</style>

 

<div id="banner">

<ul class="Limg">
  <li><a href="/"><img src="img/index1.jpg" width="475" height="300" alt="" /></a></li>
  <li><a href="/"><img src="img/index3.jpg" width="475" height="300" alt="" /></a></li>
  <li><a href="/"><img src="img/index5.jpg" width="475" height="300" alt="" /></a></li>
</ul>
<cite class="Nubbt"><span class="on">1</span><span>2</span><span>3</span></cite><br />
</div>

 
<script type="text/javascript">
//*焦点切换
(function () {
    if (!Function.prototype.bind) {
        Function.prototype.bind = function (obj) {
            var owner = this, args = Array.prototype.slice.call(arguments), callobj = Array.prototype.shift.call(args);
            return function (e) { e = e || top.window.event || window.event; owner.apply(callobj, args.concat([e])); };
        };
    }
})();
var player = function (id) {
    this.ctn = document.getElementById(id);
    this.adLis = null;
    this.btns = null;
    this.animStep = 0.2; //动画速度0.1～0.9
    this.switchSpeed =5; //自动播放间隔(s)
    this.defOpacity = 1;
    this.tmpOpacity = 1;
    this.crtIndex = 0;
    this.crtLi = null;
    this.adLength = 0;
    this.timerAnim = null;
    this.timerSwitch = null;
    this.init();
};
player.prototype = {
    fnAnim: function (toIndex) {
        if (this.timerAnim) { window.clearTimeout(this.timerAnim); }
        if (this.tmpOpacity <= 0) {
            this.crtLi.style.opacity = this.tmpOpacity = this.defOpacity;
            this.crtLi.style.filter = 'Alpha(Opacity=' + this.defOpacity * 100 + ')';
            this.crtLi.style.zIndex = 0;
            this.crtIndex = toIndex;
            return;
        }
        this.crtLi.style.opacity = this.tmpOpacity = this.tmpOpacity - this.animStep;
        this.crtLi.style.filter = 'Alpha(Opacity=' + this.tmpOpacity * 100 + ')';
        this.timerAnim = window.setTimeout(this.fnAnim.bind(this, toIndex), 50);
    },
    fnNextIndex: function () {
        return (this.crtIndex >= this.adLength - 1) ? 0 : this.crtIndex + 1;
    },
    fnSwitch: function (toIndex) {
        if (this.crtIndex == toIndex) { return; }
        this.crtLi = this.adLis[this.crtIndex];
        for (var i = 0; i < this.adLength; i++) {
            this.adLis[i].style.zIndex = 0;
        }
        this.crtLi.style.zIndex = 2;
        this.adLis[toIndex].style.zIndex = 1;
        for (var i = 0; i < this.adLength; i++) {
            this.btns[i].className = '';
        }
        this.btns[toIndex].className = 'on'
        this.fnAnim(toIndex);
    },
    fnAutoPlay: function () {
        this.fnSwitch(this.fnNextIndex());
    },
    fnPlay: function () {
        this.timerSwitch = window.setInterval(this.fnAutoPlay.bind(this), this.switchSpeed * 1000);
    },
    fnStopPlay: function () {
        window.clearTimeout(this.timerSwitch);
    },
    init: function () {
        this.adLis = this.ctn.getElementsByTagName('li');
        this.btns = this.ctn.getElementsByTagName('cite')[0].getElementsByTagName('span');
        this.adLength = this.adLis.length;
        for (var i = 0, l = this.btns.length; i < l; i++) {
            with ({ i: i }) {
                this.btns[i].index = i;
                this.btns[i]. = this.fnSwitch.bind(this, i);
                this.btns[i]. = this.fnSwitch.bind(this, i);
            }
        }
        this.adLis[this.crtIndex].style.zIndex = 2;
        this.fnPlay();
        this.ctn. = this.fnStopPlay.bind(this);
        this.ctn. = this.fnPlay.bind(this);
    }
};
var player1 = new player('banner');
</script>