You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Andrew Clark.

ASSISTANT: Ok, how can I assist you?

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

ASSISTANT: Ok, please wait.

USER: Sure, take your time.

ASSISTANT: Thank you for waiting. Sorry, no reservation found on your name to change.

USER: Oh! It may not be booked properly. Anyway, thank you for your time.

ASSISTANT: Most welcome.