You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am planned for a trip, but it is postponed unexpectedly. So please help me to change my existing reservation.

ASSISTANT: Sure, may I know your name?

USER: My name is Carol Adams.

ASSISTANT: Sorry, no reservation found on your name.

USER: Its ok, thank you for the information.

ASSISTANT: Thank you for contacting us.

USER: You are welcome.