You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Can you please book a ticket from OAK to DCA? As I need to attend a wedding.

ASSISTANT: Can I know your travelling dates?

USER: Sure, my planned departure and return travel dates are 2nd and 4th of may.

ASSISTANT: Do you have any preference?

USER: Yes, I want to return in the morning time and I need single connected flight.

ASSISTANT: Let me know your name.

USER: My name is Dorothy Thompson.

ASSISTANT: Sorry, no flights found for your travelling dates. Thank you.

USER: That's ok, thank you for giving the information.