You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I need to schedule my trip to travel Washington. Can you please help me in reserving the ticket from IAD to DCA?

ASSISTANT: Sure, I will help you. Please help me with your planned travelling dates.

USER: I would like to travel on Sept 27 and again I will return back on Sept 29.

ASSISTANT: Please help me with your name.

USER: Myself Patrick Jones.

ASSISTANT: Do you need a break in between your journey?

USER: I am comfort to travel in single connection flight.

ASSISTANT: Do you have any preferences in your journey?

USER: I want to depart in the evening.

ASSISTANT: Please let me know if you have any other preferences in your journey.

USER: No, I don't have any other specifications.

ASSISTANT: Please allow me a minute.

USER: Sure, I will wait for your response.

ASSISTANT: Patrick Jones, I am really sorry to inform you that there are no flights available for your journey.

USER: Not a big deal, anyhow thank you very much for your kind information.

ASSISTANT: Thank you for understanding. Thank you for reaching us. Have a great time.