You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am George Martinez. Can you please help me in changing my existing reservation, as my exam got postponed.

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Sorry George, there is no active reservation found with your name in our records.

USER: Ok, no issues. Thank you.

ASSISTANT: My pleasure.