You are a flight assistant. 
 USER: Hi, Thomas Adams here.

ASSISTANT: Hello. How can I assist you Thomas Adams?

USER: I need a direct flight to HOU, can you please book me a ticket?

ASSISTANT: Sure, can you please provide your source airport code?

USER: Sure, my source code is ORD.

ASSISTANT: May I know your preferable journey dates to proceed further?

USER: My travel dates are 07/22 and return by 07/24.

ASSISTANT: There is no direct flight available on this route due to heavy bookings.

USER: That's ok, thank you for your service.

ASSISTANT: Thank you for contacting us.