diff --git a/core/modules/node/node.preview.js b/core/modules/node/node.preview.js
index a9b093b..f864179 100644
--- a/core/modules/node/node.preview.js
+++ b/core/modules/node/node.preview.js
@@ -1,43 +1,50 @@
+/**
+ * @file
+ * Defines Javascript behaviors for node previews.
+ */
+
 (function ($, Drupal) {
-  "use strict";
-  /**
-   * Provide a confirmation for all links (except local fragment identifiers
-   * such as href="#frag") in node previews to warn users before leaving the page.
-   */
-  Drupal.behaviors.nodePreviewDestroyLinks = {
-    attach: function (context) {
-      $('a:not([href^=#])', context).on('click.preview', function (event) {
-        // Only confirm exiting previews when left-clicking and user is not
-        // pressing the ALT, CTRL, META (Command key on the Macintosh keyboard)
-        // or SHIFT key.
-        if (event.button === 0 && !event.altKey && !event.ctrlKey && !event.metaKey && !event.shiftKey) {
-          event.preventDefault();
-          event.stopPropagation();
-          var previewElementId = 'node-preview-dialog';
-          // Create the preview dialog element.
-          var previewElement = $('<div id="' + previewElementId + '">' +
-            '<p>Are you sure you want to exit the preview? If you navigate away ' +
-            'without saving, your changes will be lost.</p></div>').appendTo('body');
-          var dialogOptions = {
-            title: 'Exit preview?',
-            buttons: {
-              Cancel: function() {
-                $(this).dialog('close');
-              },
-              'Exit preview': function() {
-                window.top.location.href = event.target.href;
-              }
+
+"use strict";
+
+/**
+ * Provides a modal confirmation before leaving node previews.
+ */
+Drupal.behaviors.nodePreviewDestroyLinks = {
+  attach: function (context) {
+    // Display a modal confirmation for all links within preview, except
+    // for local fragment identifiers such as href="#frag".
+    $('a:not([href^=#])', context).on('click.preview', function (event) {
+      // Only confirm leaving previews when left-clicking and user is not
+      // pressing the ALT, CTRL, META (Command key on the Macintosh keyboard)
+      // or SHIFT key.
+      if (event.button === 0 && !event.altKey && !event.ctrlKey && !event.metaKey && !event.shiftKey) {
+        event.preventDefault();
+        event.stopPropagation();
+        var previewElementId = 'node-preview-dialog';
+        // Create the preview dialog element.
+        $('<div id="' + previewElementId + '"><p>' + Drupal.t('Are you sure you want to leave the preview? If you navigate away without saving, your changes will be lost.') + '</p></div>').appendTo('body');
+        var dialogOptions = {
+          title: Drupal.t('Leave preview?'),
+          buttons: {
+            Cancel: function() {
+              $(this).dialog('close');
+            },
+            'Leave preview': function() {
+              window.top.location.href = event.target.href;
             }
-          };
-          var previewDialog = Drupal.dialog('#' + previewElementId, dialogOptions);
-          previewDialog.showModal();
-        }
-      });
-    },
-    detach: function (context, settings, trigger) {
-      if (trigger === 'unload') {
-        $('a:not([href^=#])', context).off('click.preview');
+          }
+        };
+        var previewDialog = Drupal.dialog('#' + previewElementId, dialogOptions);
+        previewDialog.showModal();
       }
+    });
+  },
+  detach: function (context, settings, trigger) {
+    if (trigger === 'unload') {
+      $('a:not([href^=#])', context).off('click.preview');
     }
-  };
+  }
+};
+
 })(jQuery, Drupal);