$(function(){

$.register = {
  init: function(){
    $('.fn-fullname').blur($.register.displayName);
    $('.fn-register').validate( { errorClass: 'errorField' } );
  },
  displayName: function(){
    var name = $(this).val().split(' ');
    $('.fn-displayName').val(name[name.length-1]);
  }
};
$.register.init();

});