You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: I want to change my existing reservation. Could you help  me with that?

ASSISTANT: Sure, I am here to assist you with this. Can you please provide your name to check your reservation status?

USER: I have booked the ticket on my name Andrew Scott.

ASSISTANT: Please hold on a moment.

USER: Ok.

ASSISTANT: Andrew Scott, there is no active reservation found under your name in our database.

USER: That's ok, no problem. Thank you.

ASSISTANT: Thank you for contacting us.