Show total VAT only if VAT > 0

Change-Id: Ic4fa0dd14b36afe7fe1fef8336b36f4cd2374833
diff --git a/invoice.php b/invoice.php
index dde7e85..6bcec79 100644
--- a/invoice.php
+++ b/invoice.php
@@ -39,8 +39,6 @@
         $invoice->addItem('Conference Dinner', 'The conference dinner will take place on 20 July.', 1, false, $CONFERENCE_DINNER, $CONFERENCE_DINNER * $FULL_VAT, $CONFERENCE_DINNER);
         $vat_sum += $CONFERENCE_DINNER * $FULL_VAT;
     }
-    /* Add totals */
-    $invoice->addTotal('Total', $user->total_due);
     $lunch_count = 0;
     $lunch_details = "";
     $i = 0;
@@ -70,8 +68,14 @@
     if ($lunch_count > 0)
         $invoice->addItem('Lunch', $lunch_details, $lunch_count, false, $LUNCH, $lunch_count * $LUNCH * $FULL_VAT, $lunch_count * $LUNCH);
     // $invoice->addTotal('Discount', $STUDENT_DISCOUNT);
+
+    /* Add totals */
+    $invoice->addTotal('Gross', $user->total_due);
+
+    if ($vat_sum > 0) {
+        $invoice->addTotal('incl. VAT', $vat_sum, false);
+    }
     $invoice->addTotal('Total due', $user->total_due, true);
-    $invoice->addTotal('incl. VAT', $vat_sum, false);
 
     $invoice->addTitle("Payment Details");