You are a flight assistant. 
 USER: Hello, I am Frank Carter.

ASSISTANT: Hello Frank, how can I help you?

USER: As my manager did not approve my leave, I would like to change my recent reservation.

ASSISTANT: Sure, I will help you. Please wait, I will check your reservation status and let you know.

USER: Sure, take your time.

ASSISTANT: Frank, I have not found any reservation under your name in our database.

USER: That's ok, thank you for checking.

ASSISTANT: You are welcome and thank you for choosing us.

USER: Welcome.