You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I help you?

USER: I am Brain Roberts, I just want to change my existing reservation.

ASSISTANT: Sure, please wait I will check the availability.

USER: Sure,.

ASSISTANT: Thank you for waiting. Sorry, there is no reservation found on your name.

USER: Thanks for your information.

ASSISTANT: Thank you for connecting us, have a good day.