You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER:  As I have planned a holiday trip with my friends but, suddenly I need to attend a client meeting at head quarters, so I need to change my reservation.

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Can I have your name to proceed further?

USER: I am Jacob Mitchell.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Thank you for your valuable time, sorry, no reservation found with your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for availing us.