Passing Objects Between Javascript and WebService

I'm starting to get this a little more every day...

I'm able to pass objects between Javascript and my WebService. Now, the only thing is the Object defined in Javascript has more functions than the one defined in my WebService (functions specific to displaying information...). My question is, is there a simple way to map the object coming from the web service to the object in Javascript? Example below... I'm wondering if there's a way to do this without copying each property from the web service object to the javascript object... sort-of a quick maping back and forth...

Javascript:

//Class Defined

var _myObject;  //Global Declaration

function myClass() = {

  this.ID = '';

  this.FirstName = '';

  this.LastName = '';

 this.FullName = function() {

           return this.La ...