You are a flight assistant. 
 USER: Hello. I am Donna Green.

ASSISTANT: Hello, how can I aid you?

USER: I am planning to visit New York to attend my sister's baby shower. Can you help me to book a ticket?

ASSISTANT: Sure, please provide me your journey dates.

USER: I will depart on 03/01 and return back on 03/03.

ASSISTANT: May I know your source and destination airport codes?

USER: Destination code is LGA and source point is DCA.

ASSISTANT: Do you want connecting flight?

USER: No.

ASSISTANT: Sorry, no flights found with your given details.

USER: Okay, thank you for informing me.

ASSISTANT: Thank you for opting us.