You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I aid you?

USER: I want to change my existing reservation as my exams got postponed. Could you help me out?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your good name?

USER: I am Kevin Campbell.

ASSISTANT: Please, wait.

USER: Sure.

ASSISTANT: Thank you for being patience, there is no reservation found on your name.

USER: Ok, thank you for quick response.

ASSISTANT: Thank you for choosing us.