You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,. How can I aid you?

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

ASSISTANT: Sure, may I know your name please?

USER: Laura Thomas here.

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: Sorry Laura Thomas, there is no active reservation on your name.

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

ASSISTANT: Thanks for contacting us. Have a nice day.