You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I want your guidance to change my existing reservation, as I am the doctor I have got an appointment on the day which I have planned previously.

ASSISTANT: Sure, I will help you to change your previous reservation.

USER: Thank you.

ASSISTANT: On which name your previous reservation has been booked?

USER: I have booked the ticket under the name Patrick Turner.

ASSISTANT: Sorry, no reservation found on your name.

USER: Ok, no issues, it might have been cancelled by my assistant.

ASSISTANT: Ok, thank you for choosing us.

USER: Thank you for confirmation.

ASSISTANT: Welcome.