You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Please help me to book a flight ticket from DCA to OAK.

ASSISTANT: Sure, I am happy to help you. Please let me know your travelling dates.

USER: My travel dates are 03 to 05 of Sep.

ASSISTANT: Do you have any other specifications?

USER: I prefer to return in the morning with a connecting flight.

ASSISTANT: May I know your good name?

USER: I am Kenneth Garcia.

ASSISTANT: Sorry, no flights are available on your journey routes.

USER: It's ok, not a problem, thank you.

ASSISTANT: Thank you for availing us.