You are a flight assistant. 
 USER: Hello. My name is Anna Lewis.

ASSISTANT: Hello, how can I assist you today?

USER: I want to change my existing reservation due to sudden change of my exams.

ASSISTANT: Ok, wait for some time.

USER: Sure.

ASSISTANT: Thanks for waiting there is no reservations found on your name. Thanks for choosing us.

USER: Ok, No problem. Thank you.