diff --git a/booking.variety_form.inc b/booking.variety_form.inc
index a705fe8..1021936 100644
--- a/booking.variety_form.inc
+++ b/booking.variety_form.inc
@@ -23,12 +23,16 @@ function booking_variety_regn_form($node, &$form_state)
     ->orderBy('v.booking_variety_start');
   $result = $timeslot_query->execute();            
 
-  $form['booking_variety_regn_feedback_wrapper'] = array(
+  $form['identity'] = array(
+    '#type' => 'fieldset',
+    '#title' => 'Select Person',
+  );
+  $form['identity']['booking_variety_regn_feedback_wrapper'] = array(
     '#markup' => '<div id="booking_variety_regn_feedback_wrapper" class="form-item">Please enter your booking number from your lanyard.</div>',
   );    
-  $form['booking_nid'] = array(
+  $form['identity']['booking_nid'] = array(
     '#type' => 'textfield',
-    '#title' => t('Booking ID'),
+    '#title' => t('Booking Number'),
     '#size' => 60,	
     '#required' => TRUE,
     '#default_value' => !empty($data->booking_nid) ? $data->booking_nid : '',
@@ -41,12 +45,9 @@ function booking_variety_regn_form($node, &$form_state)
     ),	      
   );
 
-  // TODO: Update the whole form when booking ID is updated
   $form['variety-sessions'] = array(
     '#type' => 'fieldset',
     '#title' => 'Select Variety Sessions',
-    //'#prefix' => '<div id="booking_variety_session_wrapper">',
-    //'#suffix' => '</div>',    
   );  
 
   //for each entry in the variety timeslot table, create a new form select item
@@ -80,9 +81,43 @@ function booking_variety_session_callback($form, &$form_state) {
   $data = $form_state['input'];
   //watchdog('booking_debug', 'booking_variety_session_callback:<br /><pre>@info</pre>', array('@info' => print_r( $data, true)));
 
-  // TODO : Update the wrapper for booking ID validity
+  // --- Update the wrapper for booking ID validity ---
+  //verify that user-entered data is a number
+  if (! preg_match('/^[0-9]+$/', $data['booking_nid'])) {
+    watchdog('booking_debug', "<pre>booking_variety_session_callback non-numerical input</pre>");
+    $markup = '<div id="booking_variety_regn_feedback_wrapper" class="form-item"><span style="color:#8c2e0b;font-weight: bold;">' . 
+    'You have not entered a valid booking reference number.</span></div>';
+    $commands[] = ajax_command_replace('#booking_variety_regn_feedback_wrapper', $markup);
+  }	  
 
+  // Perform lookup on barcode 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'], '=');
 
+  $query = db_select('booking_person', 'p');
+  $query->condition($db_and)
+    ->fields('p');
+  $person = $query->execute()
+    ->fetchObject();	
+
+  if ($person) {
+    watchdog('booking_debug', "<pre>booking_variety_session_callback found valid attendee</pre>");
+
+    $markup = '<div id="booking_variety_regn_feedback_wrapper" class="form-item"><span style="color:#234600;font-weight: bold;">' . 
+    'Matched booking reference number.</span></div>';
+    $commands[] = ajax_command_replace('#booking_variety_regn_feedback_wrapper', $markup);
+  }
+  else {
+    watchdog('booking_debug', "<pre>booking_variety_session_callback did not find valid attendee</pre>");
+
+    $markup = '<div id="booking_variety_regn_feedback_wrapper" class="form-item"><span style="color:#8c2e0b;font-weight: bold;">' . 
+    'You have not entered a valid booking reference number.</span></div>';
+    $commands[] = ajax_command_replace('#booking_variety_regn_feedback_wrapper', $markup);
+  }
+
+  // --- Update the wrapper for available variety sessions ---
   // Query the variety timeslot table
   $timeslot_query = db_select('booking_variety_times', 'v');	
   $timeslot_query->condition('v.booking_eventid', $event->eid, '=')