You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: Can you please help me in booking my flight ticket from OAK to DCA?

ASSISTANT: Sure, may I know your planned travelling dates?

USER: My planned travelling dates are from 07/05 to 07/07.

ASSISTANT: Do you have any limits on number of connections?

USER: I need a single connecting flight.

ASSISTANT: Do you have any another specifications on your journey?

USER: No.

ASSISTANT: May I know your name for the booking process?

USER: Myself John Jackson.

ASSISTANT: Sorry, no flights are available on your required dates.

USER: It's ok, thank you for your help.

ASSISTANT: Welcome, thank you for reaching us.