You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you at this moment?

USER: I need to change my existing reservation as my plan to attend a business meeting got postponed. Can you help me in doing that?

ASSISTANT: Sure, I am here to help you with this.

USER: Thank you.

ASSISTANT: Can you please provide the name on which you have done the reservation previously?

USER: I am Timothy Phillips.

ASSISTANT: Please hold on for a moment.

USER: Sure.

ASSISTANT: Timothy Phillips, I have searched the database with your name and I didn't find any active reservation with your provided details.

USER: Ok, not an issue. Thank you for the information.

ASSISTANT: Thank you for choosing us.