--- a/booket.js	Mon Sep 29 22:39:17 2014 +0200
+++ b/booket.js	Tue Sep 30 21:32:39 2014 +0200
@@ -453,7 +453,7 @@
 var BookmarkModel = function () {
     ObservableMixin.call(this);
 
-    this.unsavedChanges = false;
+    this._unsavedChanges = false;
     this.loadFileReader = null;
     this.importFileReader= null;
     this._bookmarks = new StringMap();
@@ -466,6 +466,18 @@
 
 extend(BookmarkModel, ObservableMixin);
 
+Object.defineProperty(BookmarkModel.prototype, 'unsavedChanges', {
+    set: function (value) {
+        if (this._unsavedChanges !== value) {
+            this._unsavedChanges = value;
+            this.notify('unsaved-changes-changed', value)
+        }
+    },
+    get: function () {
+        return this._unsavedChanges;
+    }
+});
+
 BookmarkModel.prototype.add = function (bookmarks) {
     var addedBookmarkUrls = new StringSet();
 
@@ -1051,6 +1063,9 @@
     saveFormElement = document.querySelector('form#save-form');
     saveFormElement.addEventListener('submit', this);
 
+    this.unsavedChangesElement =
+        saveFormElement.querySelector('.unsaved-changes-message');
+
     this.saveLinkElement = saveFormElement.querySelector('a#save-link');
 
     loadFormElement = document.querySelector('form#load-form');
@@ -1243,6 +1258,10 @@
     window.alert('Failed to parse bookmark file:\n' + message);
 };
 
+ActionsView.prototype.onUnsavedChangesChanged = function (unsavedChanges) {
+    this.unsavedChangesElement.hidden = !unsavedChanges;
+};
+
 
 var BookmarkView = function () {
     var searchFormElement;
@@ -1623,6 +1642,8 @@
         this.actionsView.onSaveFile.bind(this.actionsView));
     this.bookmarkModel.addObserver('export-file',
         this.actionsView.onExportFile.bind(this.actionsView));
+    this.bookmarkModel.addObserver('unsaved-changes-changed',
+        this.actionsView.onUnsavedChangesChanged.bind(this.actionsView));
     this.bookmarkModel.addObserver('tag-added',
         this.tagView.onTagAdded.bind(this.tagView));
     this.bookmarkModel.addObserver('tag-count-changed',