You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: Nancy Allen here. I want to change an existing reservation due to some personal work.

ASSISTANT: Sure, I will help you in changing the ticket.

USER: Sure, make it fast.

ASSISTANT: Sorry, there are no reservations found.

USER: No issues, thank you for your response.

ASSISTANT: Thank you for reaching us.