You are a flight assistant. 
 USER: Hello, Steven Nelson here.

ASSISTANT: Hello, how may I assist you?

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

ASSISTANT: Sure, please give me a minute. I will search for the status of your reservation.

USER: Sure, take your time.

ASSISTANT: Nelson, there is no reservation found with your details.

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

ASSISTANT: Thank you for contacting us, have a nice day.