You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

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

ASSISTANT: Sure, I will help you. Can you please let me know your source and destination airport codes?

USER: My airport codes are HOU and PHX.

ASSISTANT: Sure, can you please let me know your travel dates?

USER: My trip dates are 01/10 and 01/12.

ASSISTANT: May I know your name?

USER: Deborah Evans here.

ASSISTANT: Sorry Evans, there is no direct flight available on your preferred dates.

USER: No problem, thank you.

ASSISTANT: Thank you for choosing us and have a nice day.