You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello,. How can I serve you?

USER: I want to cancel my reservation as my event got postponed. Can you help me in changing the reservation mad eon name David Lewis.

ASSISTANT: Sure, please standby.

USER: Ok.

ASSISTANT: Thanks for being on hold, there is no reservation found in your name.

USER: Ok fine. Thanks for your assistance.

ASSISTANT: Thanks for opting us. Have a nice day.