You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

USER: Please change my reservation due to sudden change in my plan for a trip.

ASSISTANT: Can I know your name?

USER: Reservation was done by the name Christine Clark.

ASSISTANT: Please wait a while.

USER: Ok.

ASSISTANT: Thanks for your time. We didn't found any reservation by this name.

USER: Fine, thanks for the information.

ASSISTANT: Thank you for contacting us.