--- includes/barcode.admin.inc	2009-11-30 23:25:25.000000000 +0100
+++ includes/barcode.admin.inc.2	2009-12-05 00:22:51.152504302 +0100
@@ -88,5 +88,43 @@ function barcode_settings() {
     '#required' => TRUE,
   );
 
+  $form['barcode_clear_images'] = array(
+    '#type' => 'checkbox',
+    '#title' => t('Flush generated barcodes'),
+    '#description' => t('Flushing all generated barcodes will result in the generation of new barcode images using the new settings. This process may however result in high server loads on sites with a lot of traffic.')
+  );
+
+  $form['#submit'] = array('barcode_settings_submit');
+
   return system_settings_form($form);
 }
+
+function barcode_settings_submit($form, &$form_state) {
+  if($form['barcode_clear_images']['#value'])
+  {
+    // User checked the 'Clear generated barcodes' checkbox
+    $barcode['file_path'] = file_directory_path() . '/' . variable_get('barcode_default_path', 'barcodes'); 
+    $barcode['image_format'] = variable_get('barcode_image_format', 'png');   
+
+    if(!file_check_directory($barcode['file_path']))
+    {
+      // Path does not exist
+      drupal_set_message(t('Path not found. No images have been deleted.'), 'warning');
+    }
+    else
+    {
+      $del_counter = 0;
+      foreach(file_scan_directory($barcode['file_path'], '.*\.'.$barcode['image_format']) as $file)
+      {
+        // Try to remove the image file
+	if(file_delete($file->filename))
+          $del_counter++;
+	else
+          drupal_set_message(t('File \''.$file->basename.'\' not found.'), 'warning');
+      }
+      drupal_set_message($del_counter.t(' barcode image(s) have been deleted.'));
+    }
+  }
+  // No need to store the checkbox value in the database
+  unset($form_state['values']['barcode_clear_images']);
+}