You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I render you?

USER: I want to book a flight ticket to Oakland with price under 200. Can you please help me with it?

ASSISTANT: Sure, can I know your planned travelling dates to proceed further?

USER: Travel dates are 10/08 and 10/10.

ASSISTANT: Do you need a stopover in between your journey?

USER: I need a single connection in between the journey.

ASSISTANT: May I know your exact airport codes?

USER: Airport codes are DCA-OAK.

ASSISTANT: May I know your name?

USER: My name is Richard Green.

ASSISTANT: Thanks for providing your details, there are no flights found with your essential details.

USER: Ok, no issues.

ASSISTANT: Thanks for opting us.

USER: Thanks for the help.