You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Can you please help me to change my existing reservation?

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

USER: I am James Hernandez.

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: It's ok, thank you.

ASSISTANT: Thank you very much for contacting our agency.