You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I want to visit Houston to attend my conference meeting. Please help me in booking my ticket from DFW.

ASSISTANT: Sure, can you please tell me your trip dates?

USER: Sure, my trip dates are from 11/30 to 12/02.

ASSISTANT: In Houston, on which airport you want to land?

USER: I want to land on HOU.

ASSISTANT: Ok do you any other requirements?

USER: Yes, my depart time will be in the afternoon with 1 connecting flight.

ASSISTANT: May I know your name please?

USER: Myself Charles Clark.

ASSISTANT: Sorry Charles, there is no flight available on these route.

USER: It's ok, thank you for your help.

ASSISTANT: Most welcome.