diff --git a/misc/drupal.js b/misc/drupal.js
index 3cebbd2..6a798dd 100644
--- a/misc/drupal.js
+++ b/misc/drupal.js
@@ -383,4 +383,14 @@ Drupal.theme.prototype = {
   }
 };
 
+/**
+ * Show elements with the 'js-show' class. These elements will not be shown if
+ * JavaScript is disabled.
+ */
+Drupal.behaviors.jsShow = {
+  attach: function(context, settings) {
+    $('.js-show', context).show();
+  }
+};
+
 })(jQuery);
diff --git a/modules/node/node.pages.inc b/modules/node/node.pages.inc
index facc7f6..644ecb1 100644
--- a/modules/node/node.pages.inc
+++ b/modules/node/node.pages.inc
@@ -386,7 +386,7 @@ function theme_node_preview($variables) {
 
   // Do we need to preview trimmed version of post as well as full version?
   if ($trimmed != $full) {
-    drupal_set_message(t('The trimmed version of your post shows what your post looks like when promoted to the main page or when exported for syndication.<span class="no-js"> You can insert the delimiter "&lt;!--break--&gt;" (without the quotes) to fine-tune where your post gets split.</span>'));
+    drupal_set_message(t('The trimmed version of your post shows what your post looks like when promoted to the main page or when exported for syndication.<span class="js-hide"> You can insert the delimiter "&lt;!--break--&gt;" (without the quotes) to fine-tune where your post gets split.</span>'));
     $output .= '<h3>' . t('Preview trimmed version') . '</h3>';
     $output .= $trimmed;
     $output .= '<h3>' . t('Preview full version') . '</h3>';
diff --git a/modules/system/system.base.css b/modules/system/system.base.css
index a6748de..b8b3116 100644
--- a/modules/system/system.base.css
+++ b/modules/system/system.base.css
@@ -198,10 +198,13 @@ tr .ajax-progress .throbber {
 }
 
 /**
- * For anything you want to hide on page load when JS is enabled, so
- * that you can use the JS to control visibility and avoid flicker.
+ * Styles for anything you want to hide on page load under certain conditions,
+ * so that you can use the JS to control visibility and avoid flicker.
+ *
+ * Use the class 'js-hide' to hide an element if JavaScript is enabled.
+ * Use the class 'js-show' to show an element only if JavaScript is enabled.
  */
-html.js .js-hide {
+html.js .js-hide, .js-show {
   display: none;
 }