You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

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

ASSISTANT: Sure, please wait a minute.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no reservation found on your name to change.

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

ASSISTANT: Thank you for approaching us.