You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I am a scientist and I have to do research on plants at SFO location, can you please book a flight ticket for me from DCA locations?

ASSISTANT: Sure, may I know your planned travel dates?

USER: Thank you and my planned travel dates are May 2nd and I will return back on May 4th.

ASSISTANT: May I know your connection limit?

USER: I will prefer to travel in single connected flight.

ASSISTANT: Do you have any other specifications?

USER: I would like to return back in evening time.

ASSISTANT: Your good name please.

USER: My name is Kathleen Roberts.

ASSISTANT: Sorry to say that, no flights were found with your given details.

USER: Sad to hear that one,  I can prefer any other source. Thank you for your help.

ASSISTANT: Thank you for reaching us.

USER: Welcome.