You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I'm David Roberts.

ASSISTANT: How can I assist you today?

USER: I would like to cancel my reservation due to emergency. Can you please help me with that?

ASSISTANT: Sure, I am glad to aid you. Please be on hold let me check your name in our database to cancel it.

USER: Sure, take your time.

ASSISTANT: Thank you for your patience. Sorry Roberts, there is no reservation found under your name in our database to cancel it.

USER: Ok, no issues. Thank you for checking.

ASSISTANT: Thank you for opting us.