diff --git a/booking.variety_form.inc b/booking.variety_form.inc
index 89963bf..6aae887 100644
--- a/booking.variety_form.inc
+++ b/booking.variety_form.inc
@@ -130,27 +130,30 @@ function booking_variety_session_form_callback($form, &$form_state) {
   //$form['form']['variety-sessions']['booking_feedback_wrapper']['#markup'] = '<div id="booking_feedback_wrapper">Test</div>';
   //return $form['form']['variety-sessions'];
 
-  // Perform lookup on person to make sure it matches someone attending the current event
-  $db_and = db_and();
-  $db_and->condition('p.booking_eventid', $event->eid, '=');
-  $db_and->condition('p.booking_status', 1, '=');
-  $db_and->condition('p.nid', $data['booking_nid'], '=');
-  $db_and->condition('p.booking_lastname', $data['booking_lastname'], '=');
+  if (isset($data['booking_nid']) && isset($data['booking_lastname'])) {
+    // Perform lookup on person to make sure it matches someone attending the current event
+    $db_and = db_and();
+    $db_and->condition('p.booking_eventid', $event->eid, '=');
+    $db_and->condition('p.booking_status', 1, '=');
+    $db_and->condition('p.nid', $data['booking_nid'], '=');
+    $db_and->condition('p.booking_lastname', $data['booking_lastname'], '=');
 
-  $query = db_select('booking_person', 'p');
-  $query->condition($db_and)
-    ->fields('p');
-  $person = $query->execute()
-    ->fetchObject();  
+    $query = db_select('booking_person', 'p');
+    $query->condition($db_and)
+      ->fields('p');
+    $person = $query->execute()
+      ->fetchObject();  
 
-  // Update feedback based on query result
-  if (! $person) {
-    $form['form']['identity']['booking_feedback_wrapper']['#markup'] = '<div id="booking_feedback_wrapper">Identity not found.</div>';
-  }
-  else {
-    $form['form']['identity']['booking_feedback_wrapper']['#markup'] = '<div id="booking_feedback_wrapper">Identity matched.</div>';
+    // Update feedback based on query result
+    if (! $person) {
+      $form['form']['identity']['booking_feedback_wrapper']['#markup'] = '<div id="booking_feedback_wrapper">Identity not found.</div>';
+    }
+    else {
+      $form['form']['identity']['booking_feedback_wrapper']['#markup'] = '<div id="booking_feedback_wrapper">Identity matched.</div>';
+    }
   }
 
+
   $form_state['rebuild'] = TRUE;
   return $form['form'];
 }