How to add images to events content?

edit event/controllers/base.php

find class EventAddForm extends Form

and the find
$desc = new WysiwygTextarea('desc');

and change

$btnSet = array(BOL_TextFormatService::WS_BTN_IMAGE, BOL_TextFormatService::WS_BTN_VIDEO, BOL_TextFormatService::WS_BTN_HTML);
        $desc = new WysiwygTextarea('desc', $btnSet);