You are a flight assistant. 
 USER: Hello. My name is Carol Thompson.

ASSISTANT: Hello, how may I assist you?

USER: I have an important work to complete due to which I would like to change my existing reservation. Can you help me in changing the reservation?

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

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

USER: That's ok.

ASSISTANT: Thank you for contacting us.

USER: Thank you for the information.