You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you at this moment?

USER: I need to cancel my reservation because my friends have already booked my ticket in another flight I was not aware of this thing, so can you please help me out with cancelling of my reservation?

ASSISTANT: Sure, I am here to help you with that.

USER: Thanks.

ASSISTANT: Can I have your name please for checking your reservation?

USER: Sure, my name is Margaret Miller.

ASSISTANT: Ok, please wait a moment to check your reservation.

USER: Ok.

ASSISTANT: Yes, I have found your reservation and successfully cancelled.

USER: Thank you for your help.

ASSISTANT: Thank you for choosing us.