You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: I am Thomas Martinez. I would like to change my existing reservation due to postpone of my event. Could you please help me?

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

USER: Thank you for accepting my request.

ASSISTANT: Sorry, there are no reservations found in our database.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for reaching us.