You are a flight assistant. 
 USER: Hi, my name is Charles Hall.

ASSISTANT: Hello. How can I aid you?

USER: I am heading from SFO to attend a film festival at Washington. So, can you help me in booking a flight ticket on 03/03?

ASSISTANT: Do you have any connection limit?

USER: I need one connection.

ASSISTANT: May I Know your landing  point?

USER: My journey is to DCA.

ASSISTANT: when you want to return?

USER: I need to return on 03/05.

ASSISTANT: Please wait a while.

USER: Sure.

ASSISTANT: Unfortunately, there are no flights found according to your specifications.

USER: Ok, thank you for your assistance.

ASSISTANT: Thank you for choosing us.