You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I would like to spend some more days with my brother, please help me in changing my existing reservation.

ASSISTANT: Sure, please provide the name for checking the reservation.

USER: My name is Timothy Mitchell.

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: There is no reservation is found under your name.

USER: Ok, no issue. Thank you for your information.

ASSISTANT: Welcome, have a great day.