When you compare to only one coupon code everything works fine.
<?php
if(isset($_POST['Coupon_Code'])) {
if($_POST['Coupon_Code'] != "airflight") {
$_SESSION['badCoupon'] = "yes";
} else {
$_SESSION['badCoupon'] = "no";
}
}
?>
This code works fine. Its the code for three coupon codes that isn't working
<?php
if(isset($_POST['Coupon_Code'])) {
if(($_POST['Coupon_Code'] != "airflight") || ($_POST['Coupon_Code'] != "facebook") || ($_POST['Coupon_Code'] != "pinterest")) {
$_SESSION['badCoupon'] = "yes"; }
else {
$_SESSION['badCoupon'] = "no";
}
}
?>