设置外部样式坐标的位置

<style type="text/css">
#main{text-align:center; background-color:#9FF; height:600px;800px}
#adver{
    position:absolute;
    left:50px;
    top:30px;
    z-index:2;
}
 
</style>
<script src="js/scroll.js"></script>
</head>
<body>
<div id="adver"><img src="images/adv.jpg"/></div>

<div id="testDiv" style="position:absolute;left:300px;top:50px;background-color:red; 80px; height:200px">内部样式的div</div>

<input   type="button"   value="测试外部样式坐标位置" onClick="test('adver')"/>


<div id="main">网页内容</div>
</body>

function test (divID){
    var divObj=document.getElementById(divID);
    
    var leftValue,leftValue;
    
    //alert(    .appName);   //使用navigator判断有时不准确，例如：在FF下运行判断为Netscape
    
    if(divObj.currentStyle){  //IE
        leftValue=divObj.currentStyle.left;
        topValue=divObj.currentStyle.top;
    }else{  //FF
        leftValue=document.defaultView.getComputedStyle(divObj,null).left;
        topValue=document.defaultView.getComputedStyle(divObj,null).top;
    }
    
     
    alert("left="+leftValue+"
top="+topValue);   
    divObj.style.left=parseInt(leftValue)+200+"px";
    divObj.style.top=parseInt(topValue)+100+"px";
}