Index: wp-admin/custom-header.php
===================================================================
--- wp-admin/custom-header.php	(revision 22081)
+++ wp-admin/custom-header.php	(working copy)
@@ -538,10 +538,13 @@
 		$image_library_url = remove_query_arg( 'TB_iframe', $image_library_url );
 		$image_library_url = add_query_arg( array( 'context' => 'custom-header', 'TB_iframe' => 1 ), $image_library_url );
 	?>
-	<p>
+	<p class="hide-if-no-js">
 		<label for="choose-from-library-link"><?php _e( 'Or choose an image from your media library:' ); ?></label><br />
 		<a id="choose-from-library-link" class="button thickbox" href="<?php echo esc_url( $image_library_url ); ?>"><?php _e( 'Choose Image' ); ?></a>
 	</p>
+	<p class="hide-if-js">
+		<strong><?php _e( 'You need Javascript to choose a header image from the Media Library.' ); ?></strong>
+	</p>
 	</form>
 </td>
 </tr>
Index: wp-admin/custom-background.php
===================================================================
--- wp-admin/custom-background.php	(revision 22081)
+++ wp-admin/custom-background.php	(working copy)
@@ -267,10 +267,13 @@
 		$image_library_url = remove_query_arg( 'TB_iframe', $image_library_url );
 		$image_library_url = add_query_arg( array( 'context' => 'custom-background', 'TB_iframe' => 1 ), $image_library_url );
 	?>
-	<p>
+	<p class="hide-if-no-js">
 		<label for="choose-from-library-link"><?php _e( 'Or choose an image from your media library:' ); ?></label><br />
 		<a id="choose-from-library-link" class="button thickbox" href="<?php echo esc_url( $image_library_url ); ?>"><?php _e( 'Choose Image' ); ?></a>
 	</p>
+	<p class="hide-if-js">
+		<strong><?php _e( 'You need Javascript to choose a background image from the Media Library.' ); ?></strong>
+	</p>
 	</form>
 </td>
 </tr>