You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

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

ASSISTANT: Sure, may I know your name please?

USER: Sure, my name is Patrick Collins.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry Collins, there is no reservation found on your name to change your reservation.

USER: No problem, I will search another flight.

ASSISTANT: Thank you for contacting us.

USER: Thank you for your information.

ASSISTANT: You are welcome.