You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I support you today?

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

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Can I have your name please?

USER: My name is William Smith.

ASSISTANT: Ok, please wait for a few minutes.

USER: Sure, take your time.

ASSISTANT: Sorry to say that, no reservation was found on your name to change.

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

ASSISTANT: Thank you for choosing us.