You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: Richard Lewis here. I would like to book a ticket from LGA to DCA.

ASSISTANT: Sure, will you mention your travelling dates please?

USER: My travel dates are as follows Dec 03 and Dec 04.

ASSISTANT: Do you have any specifications?

USER: I would like to travel in the economy class with single connection.

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no flights found under your preferable details.

USER: No problem, thank you for your time.

ASSISTANT: Welcome, have a great day.