You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: Can you please book me a flight ticket from LAS to DCA to meet my family?

ASSISTANT: Sure, please share me your trip dates.

USER: I have planned to travel on Dec 12th and return on Dec 14th.

ASSISTANT: Do you need direct flight or connecting flight?

USER: I like direct flight.

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

USER: Joshua Parker.

ASSISTANT:  Would you let us know if you have any other preferences?

USER: I want to depart at morning time and return at afternoon time.

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

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for opting us.