You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Frank Walker.

ASSISTANT: How can I assist you at this moment?

USER: Can yuo help me in changing my recent reservation, as my exam is postponed?

ASSISTANT: Sure Walker, I will help you with that.

USER: Ok.

ASSISTANT: Please wait a moment to check your reservation status.

USER: Sure.

ASSISTANT: Sorry Frank Walker, no reservation has found under your name to change.

USER: That's ok, thank you.

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