onEventSave empty field

Hi, i’m trying to create control for empty field on lightbox. I’ve find an example on documentation in onEventSave event.
I’ve tried to implement this in my code but it return always “undefined”, where i’m wrong?

<!doctype html>

Prenotazioni Edilizia Privata html, body{ margin:0px; padding:0px; height:100%; overflow:hidden; } .dhx_cal_event { z-index: 1; cursor: pointer; } .highlighted_timespan { background-color: #87cefa; opacity:0.5; filter:alpha(opacity=50); cursor: pointer; z-index: 0; } .fat_lines_section { background-image: url(data/imgs/fat_lines.png); } .my_event { background-color: #add8e6; border: 1px solid #778899; overflow: hidden; } .dhx_cal_select_menu.my_event div { border: 0; background-color: transparent; color: black; } .dhx_cal_event.my_event .my_event_body { padding-top: 3px; padding-left: 5px; } .my_event .event_date { font-weight: bold; padding-right: 5px; } .my_event_resize { height: 3px; position: absolute; bottom: -1px; } .my_event_move { position: absolute; top: 0; height: 10px; cursor: pointer; }

in your code you have the following lines

scheduler.attachEvent("onEventSave",function(event_id,native_event){ var denom = scheduler.formsection('Denominazione');
instead of scheduler.formsection it should be scheduler.formSection … ction.html