Does passport change affect appointment date?

[pkt]

My parents are planning to visit us in March. I have got appointment dates for them together in Jan 2005. We need to give the passport number and other details when we get the appointment.
There was a 2 letter spelling mistake in my father's passport, so he corrected that to make it consistent with my mother's passport. ie., the spouse name in my father's passport had 2 letter written differently. Now the passport office is giving him a new passport and the passport number will change.

Will this cause a problem in the visa appointment? Because I booked the appointment with the old passport number and now he has the new passport number. I think they will attach the old passport with the new one ( as they did it for me when I changed something ).

Please let me know if the new passport will affect anything in the visa appointment? Do I need to get another new appointment now because he change the passport?? Will there be any problems in the interview?
Your comments will be very helpful.
Thank you.

[immihelp]

Best thing is ask TTS or VFS, as applicable.

Once you find out, post here for benefits of others.

[pkt]

Sure, I will post the answers once I find out.
How do I contact TTS or VFS? Who is VFS?
Is there a phone number which they answer such questions or any email id which they use to answer these questions?

Thanks.

[immihelp]

TTS or VFS is the place where you scheduled an appointment.

Look at https://www.immihelp.com/usa-visas/visitor under 'Application' section for their contact details .