<script type="text/javascript">

 function person(name){//带参数的构造函数

     this.name=name; //定义并初始化属性

     this.SayHello=function(){//定义对象方法

         alert("hello I`m " + this.name);

     }

 }

 function Employee(name,salary){

     person.call(this,name);//用call调用父构造函数，this指当前的构造函数Employee，所以就是用person替换Employee

     this.salary=salary;

 this.showMe=function(){  alert(this.name + "$" + this.salary);   }  }   var BillGates=new person("Bill Gates");//创建person类的Billgates对象  var SteveJobs=new Employee("Steve Jobs",1234);//创建Employee类的stevejobs对象   BillGates.SayHello();//输出hello I`m Bill Gates  SteveJobs.SayHello();//输出hello I`m Steve Jobs  SteveJobs.showMe();//输出Steve Jobs $ 1234  </script>