You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I would like to book a ticket from DCA to HOU, can you please help me with that?

ASSISTANT: Sure, may I know the travelling dates?

USER: The travel dates are from 12/26 to 12/28.

ASSISTANT: Do you have any connection limit?

USER: I need a flight with 1 connection limit.

ASSISTANT: Do you have any other requirements?

USER: No.

ASSISTANT: May I know your name?

USER: Stephen Young here.

ASSISTANT: Please wait a minute.

USER: Ok.

ASSISTANT: Sorry, no flights found with your chosen dates.

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

ASSISTANT: Thank you for opting us.