You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I would like to visit The Liberty bell in Philadelphia, can you please book a flight from Washington?

ASSISTANT: Sure, I am here to help you. Do you need any connection in between the journey?

USER: No, I am looking for a direct flight.

ASSISTANT: Ok, please share your travelling dates.

USER: I will start on Oct 14th and will return back on Oct 16th.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: Please let me know your airport codes.

USER: I will fly from DCA to PHL.

ASSISTANT: May I know your name please to proceed further?

USER: Sure, my name is Ryan Carter.

ASSISTANT: Wait a minute please.

USER: Sure.

ASSISTANT: Thank you for waiting, we are sorry no fights found with your details.

USER: No worries, thank you.

ASSISTANT: Thank you for reaching us, have a good day.