You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Melissa Wilson.

ASSISTANT: Hoe can I help you?

USER: I got to know that the service of the Delta airlines is not good, so I want to cancel my reservation.

ASSISTANT: Sure, just a second.

USER: Ok.

ASSISTANT: I am sorry no reservation found on your name Mr.Melissa Wilson.

USER: That's fine, thank you for your help.

ASSISTANT: Thank you.