I filed petitoin to change to H4 from F1 in June 08. My F1 is in OPT from Jan 08 to Jan 09 and I want to work with OPT EAD for a company. H4 is still in process, not approved yet. Is it okay for me to cancel the H4 petition? Is there any form to fill out and should I have to pay for cancellation, and how much? Thanks all.