You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: Due to some personal reasons. I want to change my reservation, can you help me with it?

ASSISTANT: Sure, I can help you with that. May I know your name to check for the previous reservation in our data base?

USER: Sure, the booking is done in the name of Charles Turner.

ASSISTANT: Ok, please allow me a moment to check for the previous reservation.

USER: Sure, take your time.

ASSISTANT: Charles, there is no reservation found under your name.

USER: That's ok, may be it is already changed. Anyway thanks for your assistance.

ASSISTANT: You are welcome. Thank you for contacting us.