Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.773
diff -u -p -r1.773 common.inc
--- includes/common.inc	24 Jun 2008 22:09:52 -0000	1.773
+++ includes/common.inc	27 Jun 2008 12:48:08 -0000
@@ -2212,6 +2212,7 @@ function drupal_add_tabledrag($table_id,
   static $js_added = FALSE;
   if (!$js_added) {
     drupal_add_js('misc/tabledrag.js', 'core');
+    drupal_add_js('misc/unsaved.js', 'core');
     $js_added = TRUE;
   }
 
Index: misc/tabledrag.js
===================================================================
RCS file: /cvs/drupal/drupal/misc/tabledrag.js,v
retrieving revision 1.18
diff -u -p -r1.18 tabledrag.js
--- misc/tabledrag.js	24 Jun 2008 16:52:18 -0000	1.18
+++ misc/tabledrag.js	27 Jun 2008 12:48:08 -0000
@@ -447,6 +447,7 @@ Drupal.tableDrag.prototype.dropRow = fun
       self.rowObject.markChanged();
       if (self.changed == false) {
         $(Drupal.theme('tableDragChangedWarning')).insertBefore(self.table).hide().fadeIn('slow');
+        Drupal.markPageUnsaved(); // add warning popup
         self.changed = true;
       }
     }
Index: misc/unsaved.js
===================================================================
RCS file: misc/unsaved.js
diff -N misc/unsaved.js
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ misc/unsaved.js	27 Jun 2008 12:48:09 -0000
@@ -0,0 +1,41 @@
+// $Id:$
+
+/*
+ * Called when there is unsaved data on the page to warn users leaving
+ * (or reloading) page that they would lose their changes.  The
+ * onbeforeunload event works in FF, IE and Safari, but not in Opera
+ * (yet).  The form of the dialog is unmodifiable:
+ *  
+ * Are you sure you want to navigate away from this page?
+ * Your message here
+ * Press OK to continue, or Cancel to stay on the current page.
+ */
+Drupal.markPageUnsaved = function(msg) {
+  if (!$('body').is('.has-unsaved-changes')) { // Only do it once.
+    $('body').addClass('has-unsaved-changes');
+    if (!msg) { // default message
+      msg = Drupal.t("If you continue your unsaved changes will be lost.");
+    }
+    window.onbeforeunload = function(event) {return msg;};
+    // Allow submit buttons to not get warning message.
+    Drupal.behaviors.unsaved($('body'));
+  }
+};
+
+/*
+ * All submit buttons and image buttons need to remove the
+ * onBeforeUnload event so the warning message does not come up on
+ * form submission.  Needs to be a behavior so forms that get added by
+ * AJAX/AHAH can still submit without warning.
+ */
+Drupal.behaviors.unsaved = function(context) {
+  if ($('body').is('.has-unsaved-changes')) {
+    $(':submit,input:image', context).not('.unsaved-processed').each(function() {
+      $(this).addClass('unsaved-processed');
+      $(this).click(function() {
+        // Turn off the warning before submit triggers it.
+        window.onbeforeunload = null;
+      });
+    });
+  }
+};