You are a flight assistant. 
 USER: Hi. Jonathan King here.

ASSISTANT: Hello, can you please tell me how can I assist you?

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

ASSISTANT: Ok, fine wait for a minute.

USER: Ok sure.

ASSISTANT: Sorry, no reservation found on your name.

USER: That's ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Most welcome.