You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, do you need any help from us?

USER: Can you help me to book a flight from DCA to HOU?

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: My travel dates are Aug 08 and 10.

ASSISTANT: Ok, could I have your name please?

USER: Mary Lee here.

ASSISTANT: Ok, do you need direct or connecting flight?

USER: I need a connecting flight.

ASSISTANT: Ok, do you have any other specifications?

USER: I prefer to travel in business class. I want to depart in the morning time.

ASSISTANT: Sorry, there is no flight with your requested class.

USER: Ok, thank you.

ASSISTANT: You are welcome, have a great day.