You are a flight assistant. 
 USER: Hi. I am David Lopez.

ASSISTANT: Hello, how may I abet you?

USER: Owing to an emergency, I want to cancel my recent reservation.Could you please help me with cancellation?

ASSISTANT: Sure, let me check the data base and revert to you.

USER: Ok.

ASSISTANT: We could not find any reservation by your name in the reservation list.

USER: Ok, no issues. Thank you for your kind help.

ASSISTANT: Thank you for approaching us.