网页 图片放大 效果

<script language="JavaScript">
<!--
var smallX = 150; //缩略图宽度
var bigX = 800; //预览窗大小,可以任意设置
var bigY = 568;
var srcX = -1; //原图大小,可以任意设置. 如有一个为-1将使用图片原始大小
var srcY = -1;
var border = 1; //边框
var smallY,viewX,viewY,bl,isIE,vX,vY,imgo;
window.onload=function (){  //初始化数据
 isIE=window.event?1:0; //由于IE和FF对盒模型解释的差异,获取浏览器标记以便修正差异
 if (srcX==-1 || srcY==-1){srcX=bigpic.width;srcY=bigpic.height;} // 如果有一个为-1,则使用原图大小
 else{bigpic.width=srcX;bigpic.height=srcY;}
 smallY=srcY*smallX/srcX; //按比例计算出缩略图的高
 viewX=bigX/srcX*smallX; //计算缩略图的预览窗口大小
 viewY=bigY/srcY*smallY;
 bl=srcX/smallX; //得到缩放比例
 bigbox.style.borderWidth=border; //初始化预览窗
 bigbox.style.width=bigX+border*2*isIE;
 bigbox.style.height=bigY+border*2*isIE;
 view.style.borderWidth=border; //初始化小预览窗
 view.style.width=viewX-!isIE*border*2;
 view.style.height=viewY-!isIE*border*2;
 loading.style.left=bigX/2+bigbox.offsetLeft*!isIE-loading.offsetWidth/2; //初始化loading
 loading.style.top=bigY/2+bigbox.offsetTop*!isIE-loading.offsetHeight/2;
 var imga=document.body.getElementsByTagName("img") //初始化所有缩略图
 for (m=0;m<imga.length;m++)
  if (imga[m].className=="smallpic"){
   imga[m].style.borderWidth=border;
   imga[m].width=smallX;
   imga[m].height=smallY;
   imga[m].onmouseout=function(){if (isIE) bigbox.style.display='none'}
   imga[m].onmouseover=function(){if (isIE) bigbox.style.display=''}
  }
}
function move(e,o){
 if (imgo!=o){ //如果切换图片
   bigpic.style.display = 'none';
   bigpic.src=o.lowsrc; //载入新图片
   imgo=o; //imgo作为标记,避免重复载入相同图片
 }else{
  var e = window.event?window.event:e; //得到IE或FF的event
  if (!isIE){vX=e.pageX-border-o.offsetLeft;vY=e.pageY-border-o.offsetTop}
  else{vX=e.offsetX;vY=e.offsetY} //分别在FF与IE下获得相对坐标
  vX+=-viewX/2; vY+=-viewY/2; //得到缩略图的预览窗位置
  if (vX < 0) vX = 0; //边界判断,不能超出缩略图的范围
  if (vY < 0) vY = 0;
  if (vX > smallX - viewX) vX = smallX - viewX;
  if (vY > smallY - viewY) vY = smallY - viewY;
  bigpic.style.marginLeft = - vX * bl; //刷新预览窗口
  bigpic.style.marginTop = - vY * bl;
  view.style.display = 'block'; //刷新缩略图中预览窗口
  view.style.left = vX + o.offsetLeft + border;
  view.style.top = vY + o.offsetTop + border;
 }
}
//-->
</script>
<style type="text/css">
<!--
*{padding:0;margin:0}
body{background:black}
.smallpic{display:block;border:green dotted;float:left}
#bigbox{border:green solid;width:800px;height:568px;overflow:hidden;font-size:0px;float:left;}
#view{border:silver solid;width:0;height:0;font-size:0px;display:none;position:absolute;}
#loading{position:absolute;z-index:-1;font-size:20px;font-weight:bold;color:white;}
#loading img{vertical-align:middle}

//-->
</style>
<div id="view" onmousemove="if (!isIE) move(event,imgo)" onmouseout="if (!isIE) view.style.display='none'"></div><!--小预览窗//-->
<img class="smallpic" onmousemove="move(event,this)" lowsrc="http://www.whoj.net/images/b1.jpg" src="http://www.whoj.net/images/s1.jpg"><!--缩略图,lowsrc大图,src小图//-->
<img class="smallpic" onmousemove="move(event,this)" lowsrc="http://www.whoj.net/images/b2.jpg" src="http://www.whoj.net/images/s2.jpg">
<img class="smallpic" onmousemove="move(event,this)" lowsrc="http://www.whoj.net/images/b3.jpg" src="http://www.whoj.net/images/s3.jpg">
<img class="smallpic" onmousemove="move(event,this)" lowsrc="http://www.whoj.net/images/b4.jpg" src="http://www.whoj.net/images/s4.jpg">
<img class="smallpic" onmousemove="move(event,this)" lowsrc="http://www.whoj.net/images/b5.jpg" src="http://www.whoj.net/images/s5.jpg">
<div id="bigbox"><img id="bigpic" src="http://www.whoj.net/images//b1.jpg" border="0" onload="this.style.display = 'block'"><div id="loading"><img src="http://www.whoj.net/images/loading.gif" border="0"> Loading...</div></div><!--预览窗//-->