You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am David Martin. Please book a flight ticket from PHL to DCA.

ASSISTANT: David Martin, can you provide me with travel dates?

USER: Sure, My travelling dates are from May 29 to May 31.

ASSISTANT: Do you have any preferences?

USER: I need a direct flight.

ASSISTANT: Give me a moment.

USER: Sure.

ASSISTANT: Sorry to inform that, there are no direct flights.

USER: Ok, No issues. Thank you.

ASSISTANT: Thank you for contacting us.