You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What type of help you are expecting from me?

USER: Due some tornado in my existing destination, I need to do some changes my reservation. Can you help me in cancelling?

ASSISTANT: Sure, I will help you change your existing reservation. On which name your reservation has been booked?

USER: Please, check the reservation on Pamela Lewis.

ASSISTANT: Ok. Sorry, as per your name there is no reservation found in our data base.

USER: That's ok. Thank you for your help.

ASSISTANT: Welcome. Thank you for approaching us, have a nice day.