--- realname_userreference.module	2011-03-03 16:48:29.000000000 -0600
+++ Copy of realname_userreference.module	2011-03-03 16:50:09.000000000 -0600
@@ -428,19 +428,22 @@ function _realname_userreference_potenti
  * Menu callback; Retrieve a pipe delimited string of realname autocomplete suggestions for existing users
  */
 function realname_userreference_auto($field_name, $string = '') {
-  $fields = content_fields();
-  $field = $fields[$field_name];
-  $match = isset($field['widget']['autocomplete_match']) ? $field['widget']['autocomplete_match'] : 'contains';
-  $matches = array();
+   $fields = content_fields();
+   $matches = array();
+   if ( isset($fields[$field_name]) ) {
+      $field = $fields[$field_name];
+      $match = isset($field['widget']['autocomplete_match']) ? $field['widget']['autocomplete_match'] : 'contains';
 
-  $references = _realname_userreference_potential_references($field, $string, $match, array(), 10);
-  foreach ($references as $id => $row) {
-    // Add a class wrapper for a few required CSS overrides.
-    $matches[$row['title']] = '<div class="reference-autocomplete">'. $row['rendered'] .'</div>';
-  }
-  drupal_json($matches);
+      $references = _realname_userreference_potential_references($field, $string, $match, array(), 10);
+      foreach ($references as $id => $row) {
+         // Add a class wrapper for a few required CSS overrides.
+         $matches[$row['title']] = '<div class="reference-autocomplete">'. $row['rendered'] .'</div>';
+      }
+   }
+   drupal_json($matches);
 }
 
+
 /**
  * FAPI theme for an individual elements.
  *