You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, could you please tell us for what help you approached us?

USER: I want to cancel my reservation, so please help me in the cancellation.

ASSISTANT: Ok, could I have your name please?

USER: Myself David Lopez.

ASSISTANT: Ok, please allow me a moment.

USER: Ok.

ASSISTANT: I have found your reservation and I cancelled it.

USER: Thank you.

ASSISTANT: Thank you for choosing us, have a great day.