creating robust get/set properties in JavaScript

ECMAScript 5 has get/set properties creation [ Object.defineProperty() ]

however I find this is still too fragile - you can try to get the value for a non-existing property, with no error.

so here is some code to make get/set functions for a property, which can be more robust:

 /** @description Try to create robust code to get/set a property  
 */  
 var createRobustProperty = function (target, name) {  
   //NOT using Object.defineProperty since it means client still can call non-existent get property -> 'undefined' result!  
   target['get' + name] = function() {  
     return target['_' + name];  
   };  
   target['set' + name] = function(value) {  
     target['_' + name] = value;  
   };  
 };  
 //test:  
 var Car = function() {  
   createRobustProperty(this, 'Color');  
 };  
 var c1 = new Car();  
 c1.setColor('red');  
 console.log('car color = ' + c1.getColor());  
 //c1.getcolor() //error - no such property!