+ $closeBtn = jQuery( '#TB_closeWindowButton' );
+ /*
+ * If the native Close button icon is visible, move focus on the button
+ * (e.g. in the Network Admin Themes screen).
+ * In other admin screens is hidden and replaced by a different icon.
+ */
+ if ( $closeBtn.find( '.tb-close-icon' ).is( ':visible' ) ) {
+ $closeBtn.focus();
+ }
+