You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am frank Thomas.

ASSISTANT: How can I assist you at this moment?

USER: I am planning to change my reservation.

ASSISTANT: Sure, I will help you with this. Frank Thomas, there is no active reservation found under your name in our database.

USER: That's ok.

ASSISTANT: Thank you for contacting us.

USER: Thank you.