You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am David Davis. I would like to change my existing reservation. Could you help me out?

ASSISTANT: Sure, please hold on for a moment, let me check.

USER: Sure, please take your time.

ASSISTANT: Can I know your preferable dates?

USER: I want to travel from CLT to LGA. Travel dates are from 09/05 and return back on 09/07.

ASSISTANT: I found a flight 1008 of Delta airlines matches with your preferences, can I proceed?

USER: Yes, please go ahead.

ASSISTANT: Your ticket is booked.

USER: Thank you for the help.

ASSISTANT: Thank you, have a good day.