You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I am Lisa Hernandez. Due to my ill health, I am unable to travel. Please help me in cancelling my recent reservation.

ASSISTANT: Sure, I will help you in cancelling the ticket.

USER: Thank you.

ASSISTANT: Sorry, there are no reservations found in our database.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us.