You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I be of your service?

USER: Can you help me in changing existing reservation?

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

USER: Rachel Carter is my name.

ASSISTANT: OK, please give me moment I will check the status and revert you.

USER: OK.

ASSISTANT: Thanks for your time. Unfortunately we did not find any reservation matching your name.

USER: OK, thanks for your information.

ASSISTANT: Thanks for reaching us.