You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am William Miller.

ASSISTANT: What can I do for you?

USER: I am planning to cancel my recent reservation, because of emergency. Can you help me?

ASSISTANT: Yes, give me a moment.

USER: Sure.

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

USER: That's really sad. Thank you for your help.

ASSISTANT: Thank you for reaching us.