javascript将函数赋给属性 ,赐教

Question

function Employ(name,salary){
this.name=name;
this.salary=salary;
this.getSalary=function(){
return this.salary;
};
this.addSalary=addSalary;
}
function addSalary(addtion){
return this.salary+=addtion;
}
var e1 = new Employ("cici",100);
var e2 = new Employ("titi",50);
e1.getSalary.owner="e1";
e2.getSalary.owner="e2";
alert(e1.getSalary.owner);
alert(e2.getSalary.owner);

e1.addSalary(30).owner="e1";
                                e2.addSalary(30).owner="e2";
                                alert(e1.getSalary.owner);//**
alert(e2.getSalary.owner);//**
为什么 **标记的两行不输出同样的值"e2"?
而是一个输出 "e1" 一个输出"e2"?

Answer 1

e1.getSalary.owner="e1"; 
e2.getSalary.owner="e2"; alert(e1.getSalary.owner);//** e1
alert(e2.getSalary.owner);//** e2  ，本来就不一样啊
你是不是问反了????? 

Answer 2

搞懂了是这样:
function Employ(name,salary){
this.name=name;
this.salary=salary;
this.getSalary=function(){
return this.salary;
};
this.addSalary=addSalary;
}
function addSalary(addtion){
return this.salary+=addtion;
}
var e1 = new Employ("cici",100);
var e2 = new Employ("titi",50);
                               //给 getSalary函数添加属性
e1.getSalary.owner="e1";
alert(e1.getSalary.owner);//输出"e1"
alert(e2.getSalary.owner);//输出undifined
//如果e1 e2两个对象指向同一个getSalary函数对象 则都应该输出"e1"                                 //给addSalary函数添加属性
e1.addSalary.owner="e1";
alert(e1.addSalary.owner);//输出"e1"
alert(e2.addSalary.owner);//输出"e1"
                               //e1 e2 指向同一个addSalary 函数