public static function isValidCurrency($postedParam) 
	{
		$isValid = false;

		if(isset($postedParam['currency'])) {

			$currency = $postedParam['currency'];
			$currencyEmpty = CheckoutApi_Lib_Validator::isEmpty($currency);

			if(!$currencyEmpty){
				$isCurrencyLen = CheckoutApi_Lib_Validator::isLength($currency, 3);

				if($isCurrencyLen) {
					$isValid = true;
				}
			}
		}

		return $isValid;
	}