You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Owing to emergency I want to change my existing reservation. Can you please help me out with this?

ASSISTANT: Yes, we are here to serve you. May I know your name to proceed?

USER: I am Katherine Jackson.

ASSISTANT: Thank you. Unfortunately we did not find any reservation on your name.

USER: Ok,No problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your help.