eg.
back\classes\menus.php
if($element=='category' && empty($element)){
$app =& JFactory::getApplication();
$app->enqueueMessage(JText::_('MENU_WITHOUT_ASSOCIATED_MODULE'), 'error');
$app->enqueueMessage(JText::_('ASSOCIATED_MODULE_NEEDED'));
$app->enqueueMessage(JText::sprintf('ADD_MODULE_AUTO',hikashop::completeLink('menus&task=add_module&cid='.(int)$module->id.'&'.JUtility::getToken().'=1')));
}
.....
$app->enqueueMessage(JText::_( 'HIKASHOP_SUCC_SAVED' ));
MENU_WITHOUT_ASSOCIATED_MODULE, ASSOCIATED_MODULE_NEEDED, ADD_MODULE_AUTO displayed 0.00001 sec, then HIKASHOP_SUCC_SAVED displayed.
This is understandable