You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: As my visit to PHX for medical camp got postponed. Can you please help me with change my existing reservation.

ASSISTANT: Sure, may I know your name?

USER: My name is John King.

ASSISTANT: Please wait a minute.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found on your name to change.

USER: Ok, not an issue. Thank you.

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