Petitionno&name

[latha]

I have worked on my OPT for a company for 4
months and i got my LIN no. I have booked H1 and H4
slots in October and now i have changed to a new
company. My employer has just filed my H1 and the
LIN no is supposed to come in 10 days. I have to change
my petition no and petitioner`s name in the visa
application to attend the interview. Please suggest me
what to do. There are no other availbale slots also.
Can i apply for Delhi? But I have F1 rejections twice.
I would be very grateful to you if anyone would help
me out. Thanks