You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: Can you please help me in booking a flight ticket from SFO to DCA?

ASSISTANT: Sure, We are here to help you. Can I know your travelling dates?

USER: I want to fly on Apr 23 and return on Apr 25.

ASSISTANT: Do you need any break?

USER: I need a direct flight.

ASSISTANT: May I know your name?

USER: Myself Mark Williams.

ASSISTANT: Is there any other specifications?

USER: No.

ASSISTANT: Please be on hold for sometime, as I can check a flight for your journey with the best airlines.

USER: Ok.

ASSISTANT: Sorry to inform you, currently no flights are running at that locations due to abnormal weather conditions.

USER: Not ab issue. Thank you.

ASSISTANT: Thank you for reaching us.