Index: includes/form.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/form.inc,v
retrieving revision 1.442
diff -u -r1.442 form.inc
--- includes/form.inc	13 Mar 2010 22:33:05 -0000	1.442
+++ includes/form.inc	15 Mar 2010 20:48:52 -0000
@@ -958,7 +958,12 @@
     // An unchecked checkbox has a #value of numeric 0, different than string
     // '0', which could be a valid value.
     if (isset($elements['#needs_validation']) && $elements['#required'] && (!count($elements['#value']) || (is_string($elements['#value']) && strlen(trim($elements['#value'])) == 0) || $elements['#value'] === 0)) {
-      form_error($elements, $t('!name field is required.', array('!name' => $elements['#title'])));
+      if (isset($elements['#required_message'])) {
+        form_error($elements, $elements['#required_message']);
+      }
+      else {
+        form_error($elements, $t('!name field is required.', array('!name' => $elements['#title'])));
+      }
     }
 
     // Call user-defined form level validators.