function ChaoLei(){
            this.ageone = 1;
        }
        
        ChaoLei.prototype.getChaoleiValue = function(){
            return this.ageone;
        };
        
        function ZiLei(){
            this.agetwo = 2;
        }
        
        //继承了超类
        ZiLei.prototype = new ChaoLei();
        
        //添加新方法
        ZiLei.prototype={
        getZileiValue:function(){
            return this.agetwo;
        },
        
        //重写超类中的方法
        [color=#FF0000]someOtherMether[/color]:function(){
            return 3;
        }
        }
        var instance =new ZiLei();
        alert  (instance.getChaoleiValue());