You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Raymond Phillips here.

ASSISTANT: Raymond, how can I aid you today?

USER: I want to attend a Seminar in Dallas. Can you please help me for booking the flight ticket?

ASSISTANT: Sure, I am here to help you. May I know your travel dates please?

USER: My travelling dates are 10/20 and 10/22.

ASSISTANT: Ok, can you please provide your airport codes?

USER: My airport codes are HOU and DFW.

ASSISTANT: Ok, hold on for a moment. Let me check the best flight for you.

USER: Ok, I will wait.

ASSISTANT: Sorry Raymond, there are no flights available on your requested dates.

USER: Anyway, thanks for the information.

ASSISTANT: Welcome, thank you for choosing us. Have a great day.