You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: My college seminar has been postponed.Can you please help me for changing the existing reservation?

ASSISTANT: Sure, I will help you. May I know your name to search the existing reservation?

USER: Sure, my name is Laura Thomas.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Thomas sorry to inform you, there is no reservation under your name.

USER: Thank you for your information.

ASSISTANT: Thank you for contacting us. You are welcome.