You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Jack White here.

ASSISTANT: How can I aid you now?

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

ASSISTANT: Sure, may I know your travel dates please?

USER: My travel dates are from Sept 07 to Sept 09.

ASSISTANT: Let me know about your connection limit.

USER: I need a connecting flight.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: May I know your airline preference, if any?

USER: I would like to go with a normal cost.

ASSISTANT: Please, provide me your departure and arrival timings.

USER: I need to return in afternoon time.

ASSISTANT: Ok, please wait for a while.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry to say that, no flights are available as per your specifications.

USER: Ok, no issues. Thank you for the information.

ASSISTANT: Thank you for reaching us.