How to add options to <h:selectOneMenu/> of jsp using dwr?

[rnidhi]

I have got 3 <h:selectOneMenu/>'s.If i select program, schedules for that particular program should be populated and if i select a schedule,trainers allocated for that schedule gets populated.My problem is:If i select program,list is getting returned to me in my jsf bean,but i am unable to append that list to the list box.I have tried using addOptions(id,returnlist);but i got an 'object error',any body plz help me how to add options to list box.