You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,. May I help you .

USER: Please help me out from my problem. By mistake, I have booked wrong flight ticket. Can you check is there any reservation with my name Scott Thompson?

ASSISTANT: Sure Scott, you want to change the reservation or cancel the reservation.

USER: I want to change my existing reservation.

ASSISTANT: Just a second please.

USER: Yes sure, take your time.

ASSISTANT: I am sorry  Scott Thompson, I could not find reservation .

USER: It's OK. Thank you to take my problem.