You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: I am willing to change my travel dates in the past ticket, can you please help me to change the ticket details?

ASSISTANT: Sure, I will help you in changing the reservation. May I know your name please?

USER: Thank you for accepting my request.  My name is Gary Robinson.

ASSISTANT: Sorry, there are no reservations found.

USER: Oh! I think my ticket is not reserved properly. Anyways thank you for checking.

ASSISTANT: Thank you for reaching us.

USER: You are welcome.