Found by myself.
Using OnSave event and "e.event.set()"
function
scheduler_save(e) {
var
_fournisseur = $(
'#FournisseurCBB'
).val();
if
(!checkFournisseur(_fournisseur, e.event)) {
e.preventDefault();
}
var
_title = $(
'#txtTitre'
).val();
e.event.set(
"title"
, _title);
}