You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello.

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

ASSISTANT: Sure, may I know your name please?

USER: My name is Kathleen Anderson.

ASSISTANT: Ok, please be on hold.

USER: Ok.

ASSISTANT: We regret to say that, there is no reservation found on your name.

USER: Ok, no issues. Thank you for your information.

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