make previous sw question configurable

booking.admin.inc

@@ -706,6 +706,16 @@ function booking_admin() {
     ),
     '#default_value' => variable_get('booking_enable_previous_studyweeks', 0)
   );
+  $form['regn_options']['booking_require_previous_sw'] = array(
+    '#type' => 'radios',
+    '#title' => t('Require attendees to select number of previous study weeks?'),
+    '#description' => t('Select whether to require attendees to choose the number of study weeks they previously attended. Doesn\'t have any effect if previous studyweek question is not enabled above.'),
+    '#options' => array(
+      0 => t('No'),
+      t('Yes')
+    ),
+    '#default_value' => variable_get('booking_require_previous_sw', 0)
+  );  
   $form['management'] = array(
     '#type' => 'fieldset',
     '#title' => 'Data Management Options',

booking.regn_form.inc

@@ -961,10 +961,11 @@ function booking_form($node, &$form_state, $inserting = FALSE)
     );
   }
   if (variable_get('booking_enable_previous_studyweeks', 0) == 1) {
+    $prev_sw_required_check = (variable_get('booking_require_previous_sw', 1) == 1) && $inserting; 
     $form['misc-areas']['booking_prev_sw_count'] = array(
       '#type' => 'select',
       '#title' => t("How many Study Weeks have you been to previously?"),
-      '#required' => FALSE,
+      '#required' => $prev_sw_required_check,
       '#default_value' => variable_get('booking_prev_sw_count', empty($data->booking_prev_sw_count) ? '' : $data->booking_prev_sw_count),
       '#options' => _get_previous_sw_options(),
     );