You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you today?

USER: I want to change my existing reservation, can you please help me out?

ASSISTANT: Sure, we can help you with that.

USER: Thank you.

ASSISTANT: Please let me know your name for further process.

USER: Sure, my name is Lisa Martinez.

ASSISTANT: Ok, please wait for few minutes.

USER: Sure.

ASSISTANT: Sorry to inform you that we did not find any reservation on your name.

USER: That's ok, no issue. Anyway thank you for checking.

ASSISTANT: Thank you for choosing us.