--- isbn.module.orig	Thu Sep 17 06:30:15 2009
+++ isbn.module	Fri Jan 15 23:33:32 2010
@@ -227,8 +227,29 @@
             //VALIDATE ISBN HERE
             if ($field['isbn_validation'] !== ISBN_NO_VALIDATION) {
               $valid = isbn_validate_number($item['value'], $field['isbn_format']);
-              if (!$valid) {
-                form_set_error($error_element, t('ISBN/ISSN Validation Failed'));
+              if (!isset($valid) || $valid['valid'] == false) {
+                switch ($valid['message']) {
+                    case 'confirmSuccess': 
+						form_set_error($error_element, t('Valid ISBN/ISSN number.')); 
+						break;
+                    case 'confirmFailure': 
+						form_set_error($error_element, t('Not a valid ISBN/ISSN Number.')); 
+						break;
+                    case 'notEnoughDigits': 
+						form_set_error($error_element, t('Not Enough Digits!  ')); 
+						break;
+                    case 'tooManyDigits': 
+						form_set_error($error_element, t('Too Many Digits!  '));
+						break;
+                    case 'requiredDigits': 
+						form_set_error($error_element, t(' digits are required.'));
+						break;
+                    case 'missingPrefix13': 
+						form_set_error($error_element, t('13 Digit ISBNs need to begin with 978 or 979.'));
+						break;
+                    default: 
+						form_set_error($error_element, t('ISBN/ISSN Validation Failed'));
+                }
               } 
             }           
           }