This is the portion of transition callback you have to use in the Layout
fe.add_transition_callback( this, "on_transition" )
function on_transition( ttype, var0, ttime ) {
if (ttype == Transition.ShowOverlay) {
if (var0 == Overlay.Favourite) overlay_label.msg ="Your Message Here"
}
}
and overlay_label, overlay_listbox is a text object and a listbox object defined as custom control using:
fe.overlay.set_custom_controls( overlay_label, overlay_listbox )