I am trying to create a UserDon object, and trying to generate the get and set methods programmatically ( based on Pro Javascript book by John Resig page 37 ), and am testing this on Firefox 3.5

The problem is: in function UserDon, "this" refers to the window object instead of the UserDon object.

So after calling var userdon = new UserDon(...) I got setname and getname methods created on the window object (also setage and getage).

How can I fix this?

function UserDon( properties ) {
   for( var i in properties ) {
   (function(){
      this[ "get" + i ] = function() {
        return properties[i];
      };

      this[ "set" + i ] = function(val) {
        properties[i] = val;
      };
      })();
   }
 }

var userdon = new UserDon( {
   name: "Bob",
   age: 44
});