js对象的深度克隆

Object.prototype.deepClone=function(){ 
    function cloneObj(){}    
    cloneObj.prototype=this; 
    var obj=new cloneObj(); 
    for(var o in obj){ 
        if(typeof(obj[o])=="object")obj[o]=obj[o].deepClone(); 
        }    return obj; 
}