You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I best serve you today?

USER: Please book a flight ticket to DCA to attend family meeting. Can you book a flight from CLT?

ASSISTANT: Sure, please share me your trip dates.

USER: I will fly on Aug 18 and return on Aug 20.

ASSISTANT: Is there any class preferences for you?

USER: No.

ASSISTANT: Do you need direct flight or connecting flight?

USER: I need a connecting flight.

ASSISTANT: May I know your airline preferences ?

USER: I want normal-cost airline.

ASSISTANT: For booking, we need your good name. Please provide it.

USER: My name is Sharon Robinson.

ASSISTANT: Sorry to say that, there are no flights available on the routes of your journey.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for opting us.