You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Donald Lee, want to cancel my trip as I  have changed my plans. Can you help me in this?

ASSISTANT: Sure, we are here to help you. Please hold on a minute.

USER: Sure, take your time.

ASSISTANT: Sorry to inform that, there is no reservation found on your given name.

USER: It's ok, thank you for your help.

ASSISTANT: Thanks for reaching us, have a nice day.