diff --git a/booking.variety_form.inc b/booking.variety_form.inc
index 6851dee..ffb9e8d 100644
--- a/booking.variety_form.inc
+++ b/booking.variety_form.inc
@@ -145,11 +145,14 @@ function booking_variety_regn_form_validate($form, &$form_state) {
   }
 
   // --- Check that this person hasn't already registered for variety sessions
-  $query_already_registered = db_query("SELECT * FROM {booking_variety_regn} WHERE booking_person_nid = :nid", 
-    array(':nid' => $values['booking_nid']));
+	$prev_regn_query = db_select('booking_variety_regn', 'v');
+	$prev_regn_query->condition('v.booking_person_nid', $values['booking_nid'], '=');
+	$prev_regn_check = $prev_regn_query->execute()
+		->fetchObject();
 
-  if ($query_already_registered) {
+  if ($prev_regn_check) {
     form_set_error('booking_nid', t('You have already registered for variety sessions. Existing registration cannot be changed.'));
+    watchdog('booking_debug', 'Previous variety session registration: <pre>@info</pre>', array('@info' => print_r( $prev_regn_check, true)));
   }
 
   // --- Check there is still space available in the selected variety sessions ---