You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: I am Carol Evans. I am planning to book a ticket from SFO to DCA. Can you please help me out?

ASSISTANT: Sure, I am here to help you out. Please provide me your trip dates.

USER: I am planning to travel on 01/27 and return back on 01/29.

ASSISTANT: Sorry, there is no flight in your route with your travel dates.

USER: That's fine, please proceed the booking.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your service.