You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I need to cancel my reservation due to some personal issues.So can you help me with cancellation of my reservation?

ASSISTANT: Can I know your name?

USER: I am John Gonzalez.

ASSISTANT: Sorry, there is no reservation by your name.

USER:  Not a problem, thank you for the information.

ASSISTANT: Thank you.