You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Please help me out in booking the ticket from ORD to DCA.

ASSISTANT: Sure, let me know your travelling dates.

USER: My trip dates will be Jun 14 to Jun 16.

ASSISTANT: May I know your connection limit?

USER: I need a direct flight.

ASSISTANT: Do you have any other requirements?

USER: Normal cost is my airline preference.

ASSISTANT: May I know your name please?

USER: Elizabeth Lee is my name.

ASSISTANT: Ok, please wait for a while.

USER: Ok.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: That's ok, thank you.

ASSISTANT: Thank you for opting us.