Adding a New button and handler inside lightbox

How to add a new button or control inside the light box and add an appropriate handler for that… please be elaborative with your replies…

Button in section header
docs.dhtmlx.com/doku.php?id=dhtm … ion_header

Button at form’s bottom
docs.dhtmlx.com/doku.php?id=dhtm … m_s_bottom

or you can create a custom section and render button inside of it
docs.dhtmlx.com/doku.php?id=dhtm … om_editors