? modules/node/node.content_forms.inc
? modules/system/Untitled-1
Index: modules/book/book.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/book/book.module,v
retrieving revision 1.433
diff -u -p -r1.433 book.module
--- modules/book/book.module	11 Aug 2007 14:06:15 -0000	1.433
+++ modules/book/book.module	13 Aug 2007 21:44:00 -0000
@@ -527,7 +527,14 @@ function book_remove_button_submit($form
 function book_remove_form(&$form_state, $node) {
   $form['#node'] = $node;
 
-  return confirm_form($form, t('Are you sure you want to remove %title from the book hierarchy?', array('%title' => $node->title)), 'node/'. $node->nid, array('yes' => t('Remove')));
+  if ($node->book['has_children']) {
+    $description = t('It has associated child pages, which will be relocated automatically. This may make it difficult to recover the previous configuration.');
+  }
+  else {
+    $description = t('It may be added back using the Outline tab.');
+  }
+
+  return confirm_form($form, t('Are you sure you want to remove %title from the book hierarchy?', array('%title' => $node->title)), 'node/'. $node->nid,  $description, t('Remove'));
 }
 
 /**