You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Can you please help me in changing my existing reservation?

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

USER: I am Dorothy Edwards.

ASSISTANT: There is no reservation found under your name.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for choosing us.