You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to change my existing reservation. Could you help me with that?

ASSISTANT: Sure, I am here to help you for this. May I know your name please?

USER: Ryan Martinez.

ASSISTANT: Just a moment, let me check your reservation status in our records.

USER: Ok.

ASSISTANT: Sorry for inconvenience, no reservation is found under your name.

USER: That's ok, no problem. Thank you.

ASSISTANT: Thank you very much for contacting our agency.