i have a functionality in my website where when user enters email address … i validate email address that it did not exist in database if it exist i want to set errors by addErrors() method described in yii/framework/base/cmodel.php … in controller action … i know it will not work until page loads again … so i want to addError or do something similiar to that …which returns false and prevent from to get submitted untill they do not solve the error(write a unique email address)…