}
// Set cookie when default refid > 0
-if (!isSessionVariableSet('refid') || (!empty($GLOBALS['refid'])) || ((get_session('refid') == "0") && ($_CONFIG['def_refid'] > 0))) {
+if (!isSessionVariableSet('refid') || (!empty($GLOBALS['refid'])) || ((get_session('refid') == "0") && (isset($_CONFIG['def_refid'])) && ($_CONFIG['def_refid'] > 0))) {
// Set cookie
set_session('refid', $GLOBALS['refid']);
} // END - if