You are a flight assistant. 
 USER: Hello, I am Jeffrey Campbell.

ASSISTANT: Hello, how may I assist you today?

USER: I need a direct flight to attend for my brother's marriage at Houston, IAH.So, can you book a flight ticket for me?

ASSISTANT: Sure, may I know your source point?

USER: Denver, DEN is my source airport.

ASSISTANT: On what dates you are willing to travel?

USER: My travelling dates are 11/15 to 11/17.

ASSISTANT: Ok, do you need any lay by.

USER: No, I need a direct flight.

ASSISTANT: Sorry, no direct flights available with your requested dates.

USER: It's ok, no problem. Thank you for your kind information.

ASSISTANT: Thank you for reaching us.