You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How may I guide you today?

USER: Can you please help me in changing my existing reservation, as my exam got postponed.

ASSISTANT: Sure, I am mirthful to help you with that. May I know your name please?

USER: Thank you. Myself, Joseph Davis.

ASSISTANT: Please wait for a while, let me check your previous reservation status.

USER: Ok.

ASSISTANT: Thank you for waiting. There is no active reservation found on your name in our database to change it.

USER: Ok, no issues. Thank you for your help.

ASSISTANT: Thank you for reaching us, have a great day.