You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Carol Baker here.

ASSISTANT: How may I assist you?

USER: Could you book my ticket in a direct flight?

ASSISTANT: Sure, I will help you. May I know your nearest airport codes please?

USER: My airport codes are DEN and HOU.

ASSISTANT: Can I have your planned journey dates please?

USER: My trip dates are 04/15 and 04/17.

ASSISTANT: Please hold on a moment.

USER: Ok.

ASSISTANT: Carol, no flights has been found on your requirement.

USER: No problem, thank you.

ASSISTANT: Thank you for choosing us.