gistfile1.js

(function()
{
	function User()
	{
		var user = this;
		this.set = function(key, value)
		{
			user[key] = value;
		}
		this.get = function(arg)
		{
			return user[arg];	
		}
	}
	
	var bob = new User();
	bob.set('phone', '123-456-7890');
	var bobsPhone = bob.get('phone');
	
	alert(bobsPhone);

})();