You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I need your help in changing the existing reservation. Because the concert I am attending has been postponed.

ASSISTANT: Sorry to hear that. May I know your name please?

USER: My name is Katherine Adams.

ASSISTANT: Adams, I found no reservation with the details you provided.

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

ASSISTANT: You are welcome.