ok i removed the double quotes but i get a syntax error on the first line:
if (true && ((sizeof($this->Items) > 0) && (isset($_SESSION['FormCouponValue'])) && (isset($_SESSION['FormCouponValidFrom'])) && (isset($_SESSION['FormCouponValidTo'])) && (time() >= strtotime('$_SESSION['FormCouponValidFrom']')) && (time() <= strtotime('$_SESSION['FormCouponValidTo']')))) {
$totalDiscount += $_SESSION['FormCouponValue'];//Result