You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: I have meeting with president at White House. Can you do the reservation?

ASSISTANT: Sure, please provide your airport codes?

USER: Travelling codes are HOU-IAD. I need a direct flight.

ASSISTANT: To book a flight ticket we need your travelling days?

USER: Travelling dates are 11/29 and 12/01.

ASSISTANT: Thank you for your information, sorry to inform you that there are no flights available .

USER: No problem, Thanks for quick reply.

ASSISTANT: May I know your good name?

USER: I am Timothy Wilson.

ASSISTANT: Thank you for reaching us.

USER: Thank you.