You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Melissa Wilson here.

ASSISTANT: How can I assist you Melissa Wilson?

USER: There is a cancellation of seminar, so I need to change my reservation.

ASSISTANT: Wait a moment please, I am checking the status of your reservation.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found with your name.

USER: That's not a big deal. Thank you for searching.

ASSISTANT: Thank you for choosing our service.

USER: Welcome.