在线等，怎么让这个效果中的图片一直居中显示
我先把测试地址帖上，托管在sinaAPP，如果不想看地址的话 我把代码帖在下面看代码也可以，求大神帮忙啊。
http://1.depaer.sinaapp.com/b/
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title></title><style type="text/css">body {margin:0;padding:0;}#container {height:1154px;background:url(images/bg1.jpg) no-repeat center top;margin:0;padding:0;}#banner1 {width:100%;height:470px;margin:0 auto;padding-top:106px;}img{-ms-interpolation-mode:bicubic}section,article,aside,header,footer,nav,figure{display:block}body,h1,h2,h3,h4,h5,h6,p,blockquote,dl,dt,dd,ul,ol,li,pre,form,fieldset,legend,button,input,textarea,th,td,figure{margin:0;padding:0}/* slide */.slide{max-width:100%;height:470px;margin:0 auto;position:relative;overflow:hidden}/*修改高度*/.slide-cnt{width:100%;height:100%;position:absolute;overflow:hidden;z-index:2}.slide-cnt .slide-list{width:100%;height:100%;position:relative}.slide-cnt .slide-list li{width:100%;height:100%;position:absolute}.slide-cnt .slide-list li a{width:100%;height:100%;display:block;cursor:pointer}.slide-cnt .slide-list li a:hover{text-decoration:none}.slide-cnt .slide-page{position:absolute;z-index:10;left:50%;bottom:10px;margin-left:-52px}/*修改小点的图片*/.slide-cnt .slide-page span{display:block;float:left;width:30px;height:30px;margin-right:5px;overflow:hidden;text-indent:-30px;background:url(images/slider-sprites.png) -30px 0 no-repeat;font-style:normal;cursor:pointer}.slide-cnt .slide-page span.on{background-position:0 0;color:#fff}/* 修改下载 */.slider-download{ position:absolute; bottom:165px; left:380px; z-index:3; width:418px; height:246px; background:url(images/slider-download.png) 0 0 no-repeat; _background:url(about:blank); _filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src='images/slider-download.png',sizingMethod='scale');}.slider-download-btn{ position:absolute; display:block; width:190px; height:60px; z-index:3; _background:url(about:blank); bottom:165px; left:379px; overflow:hidden}.slider-download-btn span{ position:absolute; top:-999em; left:0}</style></head><body><div id="container"><div id="banner1"><div class="slide"> <div id="home_slide" class="slide-cnt"> <ul class="slide-list"> <li><img src="images/banner1.jpg" alt="" /></li> <li><img src="images/banner2.jpg" alt="" /></li> <li><img src="images/banner3.jpg" alt="" /></li> </ul> <cite class="slide-page"> <span class="on">1</span> <span>2</span> <span>3</span> </cite> </div> <div class="home_download"> <div class="slider-download"></div> <a class="slider-download-btn" href="download.html"><span>立即下载</span></a> </div></div></div><script>(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 glume = function(id){ this.ctn = document.getElementById(id); this.adLis = null; this.btns = null; this.animStep = 0.1;//这里修改动画切换的速度0.1～0.9 this.switchSpeed = 5;//这里修改自动播放间隔(秒) this.defOpacity = 1; this.tmpOpacity = 1; this.crtIndex = 0; this.crtLi = null; this.adLength = 0; this.timerAnim = null; this.timerSwitch = null; this.init();};glume.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].onclick = this.fnSwitch.bind(this,i); this.btns[i].onclick = this.fnSwitch.bind(this,i); } } this.fnPlay(); this.ctn.onmouseover = this.fnStopPlay.bind(this); this.ctn.onmouseout = this.fnPlay.bind(this); }};var player1 = new glume('home_slide');</script></body></html>
#container {height:1154px;background:url(http://1.depaer.sinaapp.com/b/images/bg1.jpg) no-repeat fixed top center;margin:0;padding:0;}.slide-cnt{width:100%;height:100%;position:fixed;overflow:hidden;z-index:2}