You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I want to change an existing reservation, so please help me in changing the reservation.

ASSISTANT: Sure, we are here to help you. Can I have your name?

USER: Myself Gregory Rodriguez.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

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

USER: Not an issue. Thank you.

ASSISTANT: Thank you for reaching us.