I want to clarify below listed queries.

a.)I filed H4 to F1 change of status for my wife on Feb-1-2010 and waiting for the approval notice. My wife h4 I-94 is expiring on 02-Apr-2010, so my concern is that if for some reason her F1 is denied and we get the notification after Apr-02-2010 so, can we file for her H4 visa after H4 I-94 date or can I file for her H4 extension in parallel ?

b.) I have applied for my H1b 3 year extension on Mar-12-2010 and in waiting process and my current H1b I 94 expiration date is 02-Apr-2010. If for some reason my H1b extension is denied and I get the notification some where in May or June 2010 so, can I file for F1 process by joining the university during that time or should I apply for f1 change of status in parallel ?

Thanks
Javed