How to display success message in the front-office

[pippo67]

Hello,
I created a personal module and I would like to display a successful message in the front office after running an action, example delete, as in the backend. How should I do?  In my controller I use the following method

public function initContent()
{
    parent :: initContent ();
    ...........

      ........

}

Thanks in advance and sorry for my english