You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I am Katherine Anderson.

ASSISTANT: Ok.

USER: I am looking for a flight from PHL to DCA, can you please help me in booking?

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

USER: My travelling dates are Nov 19 and Nov 21.

ASSISTANT: Do you have any specifications?

USER: I prefer normal cost airline and my return time is morning.

ASSISTANT: Do you have any other preferences?

USER: I need a direct flight.

ASSISTANT: Please give me a moment.

USER: Sure.

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

USER: That's ok, thank you for checking.

ASSISTANT: Welcome, have a great day.