You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you at this moment?

USER: I would like to change the travel dates in the past ticket because my trip got postponed, can you please help me to do that?

ASSISTANT: Sure, I am happy to help you with that. Can I have your good name please to check your reservation status?

USER: Thank you for considering my request. My name is John Martin.

ASSISTANT: Ok, please be on hold for a moment.

USER: Ok, take your own time.

ASSISTANT: Sorry John Martin, no reservation has found under your name to change.

USER: It's ok, not a problem. Thank you for the information.

ASSISTANT: Thank you for choosing  us, have a good day.

USER: Most welcome.