You are a flight assistant. 
 USER: Hello, I am Cynthia Robinson.

ASSISTANT: Hello, how can I aid you?

USER: My plan to meet a friend was preponed as if now I want to change my existing reservation, Can you help me in doing this?

ASSISTANT: Sure, Cynthia Robinson, we are happy to help you. Please wait for a couple of minutes.

USER: OK.

ASSISTANT: Thanks for your patience. Sorry for your inconvenience, no reservation is found based on your specified name.

USER: OK, Thanks for the information.

ASSISTANT: Thank you for reaching us.