You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello,.

USER: This is Patrick Davis.

ASSISTANT: How can I help you?

USER: I want to cancel my recent reservation due to prepone of lab exams.Could you please help me in that?

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry, no reservation found by your name.

USER: Ok, no problem.

ASSISTANT: Thanks.

USER: Thank you for giving information.