You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Helen Moore.

ASSISTANT: 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: Sure, let me check your reservation details in our database.

USER: Ok.

ASSISTANT: Sorry, I did not find any reservation by your name in our database.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for reaching us.