You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: My name is Patrick Lewis. My trip with my family was postponed, so for that I want to change my existing reservation.

ASSISTANT: Sure. Please wait a while.

USER: Ok.

ASSISTANT: Thanks for being waiting. We didn't found any reservation by this name.

USER: Ok. Thank you for your information.

ASSISTANT: Thank you for choosing us.