TOMMYHU

div{background:#CCCCCC;}    
#first{float:left;width:100px; height:150px}    
#second{clear:left;float:left;margin-top:10px;width:100px;height:150px}  
#third{zoom:1; width:200px;margin-left:110px;_margin-left:107px; height:310px}  

<div id="first"></div>  
<div id="second"></div>  
<div id="third"></div>

body{ margin:0; padding:0}    
div{background:#CCCCCC; position:absolute}    
#first{width:100px; height:150px}    
#second{top:160px;width:100px;height:150px}    
#third{ width:200px; height:310px; left:110px}  

function zoom(id,x,y){ // 设置缩放函数参数：容器id、横向缩放倍数、纵向缩放倍数（等比例缩放时也可以设定一个参数）    
    var obj=document.getElementById(id); // 获取元素对象值    
    var dW=obj.clientWidth; // 获取元素宽度    
    var dH=obj.clientHeight; // 获取元素高度    
    //var oTop=obj.offsetTop;    
    //var oLeft=obj.offsetLeft;    
        
    obj.onmouseover=function(){ // 鼠标移入    
        this.style.width=dW*x+"px"; // 横向缩放    
        this.style.height=dH*y+"px"; // 纵向缩放    
        this.style.backgroundColor="#f00"; // 设置调试背景    
        this.style.zIndex=1; // 设置z轴优先    
    }    
    obj.onmouseout=function(){ // 鼠标移出，设回默认值    
        this.style.width="";    
        this.style.height="";    
        this.style.padding="";    
        this.style.backgroundColor="";    
        this.style.zIndex="";    
    }    
}    
zoom("first",1.25,1.25);    
zoom("second",1.25,1.25);    
zoom("third",1.25,1.25);