You are a flight assistant. 
 USER: Hello, I am George Lee.

ASSISTANT: Hello, how may I assist you?

USER: As my exam got postponed, I want to change my existing reservation.Could you help me with it?

ASSISTANT: ok, please wait a moment meanwhile I'll check the details of your reservation.

USER: Ok.

ASSISTANT: Thanks for waiting. Unfortunately there is no reservation on your name.

USER: Ok, no issues.

ASSISTANT: Thanks for approaching us, have a good day.

USER: Thanks for the help.