You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: Can you please find a flight in the route from Oakland to Washington?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: Thank you. I am willing to travel on the dates of May 15 and May 17.

ASSISTANT: Can I know your airport codes too?

USER: The nearest airport codes are OAK and DCA.

ASSISTANT: Do you need any specifications in airlines?

USER: No but please make sure that the connection limit should be at least one.  I didn't have any other preferences.

ASSISTANT: Can I know your name please?

USER: My name is Jerry Gonzalez.

ASSISTANT: Sorry, there are no flights found in our database.

USER: It's ok, I will choose some other source to travel. Anyways thank you for checking the flight availability.

ASSISTANT: Thank you for reaching us.

USER: You are most welcome.