You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I serve you?

USER: I need to change my reservation due to my planned event got postponed. So please help me with that.

ASSISTANT: Yes.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: Sure, myself Dennis Hill.

ASSISTANT: Please wait.

USER: Sure, take your time.

ASSISTANT: Thanks for waiting. But I am sorry to say that there is no flight reservation on your name to change it.

USER: Oh! It may not be booked properly due to server issues while booking. Anyway, thank you for your time.

ASSISTANT: Thank you.

USER: Most welcome.