SOURCE

 
 require(["dojo/_base/lang"], function(lang){
  // clone an object
  var obj = { a:"b", c:"d" };
  var thing = lang.clone(obj);

 var Fun =function (){
    var name = 'hank';
    this.age = 18;
    var that = this;
    this.showName = function(){
        alert(name);
    }
    this.setAge = function(age){
        that.age = age;
    }
    this.setName = function(name1){
        name = name1;
    }
    /*
    this.showAge = function(){
        alert(that.age+1);
    }*/
};

Fun.prototype.showAge=function(){
  alert(this.age);
}

var Fun2 = function(){
    this.age = 16;
}

Fun2.prototype = lang.clone(Fun.prototype);
var in1 = new Fun();
var in2 = new Fun2();
in1.showAge();
in2.showAge();
/*
var t = new Fun();
var r = new Fun();
r.setName('jame');
r.showName();
t.showName();
r.setAge(15);
r.showAge();
t.showAge();
*/
});