ZipCodeValidator.prototype = new ValidatorDecorator();
	
	ZipCodeValidator.constructor = ZipCodeValidator;
    ZipCodeValidator.baseConstructor = ValidatorDecorator;
	ZipCodeValidator.superclass = ValidatorDecorator.prototype;

	function ZipCodeValidator(validatorObject, errMsg) {
		if(arguments.length > 0)
		{
			ZipCodeValidator.baseConstructor.call(this, errMsg, validatorObject);;
		}
	}
	
	ZipCodeValidator.prototype.isValid = function(id) {
			var zipCodeField = document.getElementById(id);
			
			var re = /^\d{5}$|^\d{5}-\d{4}$/;
						
			return (re.test(zipCodeField.value));
	};