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, can you please provide with your name please?

USER: Myself Samantha Lewis.

ASSISTANT: Can you give me a moment?

USER: Ok.

ASSISTANT:  Samantha Lewis. I regret to inform that there is no reservation by your name.

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

ASSISTANT: Thank you for reaching us.