You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I want to book a flight ticket from OAk to IAD. Could you help me in booking?

ASSISTANT: Sure, can you share your trip dates?

USER: My travelling dates are from May 07 - 09.

ASSISTANT: Do you have any specifications?

USER: I prefer for direct flight in normal-cost airline.

ASSISTANT: May I know your name?

USER: John Clark.

ASSISTANT: Sorry, there is no direct flight on your given dates.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.