You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you at this moment?

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

ASSISTANT: Sure, I am here to assist you in changing the ticket  details. Can you please tell me your name?

USER: Sure, my name is Donna Miller.

ASSISTANT: Ok, please give me a moment.

USER: Sure, take your time.

ASSISTANT: I have checked in our site but I cannot find any ticket on your name to your help you out in ticket modification.

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

ASSISTANT: You are most welcome and thank you for reaching us.