You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I want to change my existing reservation. Can you help me in that?

ASSISTANT: Yes, can you tell me your name?

USER: Myself Amanda Smith.

ASSISTANT: Sorry to inform you that there is no reservation found on your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.