You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Rachel Lewis.

ASSISTANT: How may I help you out?

USER: Can you help me to book a flight from DCA to OAK?

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

USER: My travelling dates are 06/25 and 06/27.

ASSISTANT: Can I know your preferences?

USER: I want to return at afternoon.

ASSISTANT: Do you need any specifications?

USER: I need a connecting flight.

ASSISTANT: Sorry, there are no flights found.

USER: No issues, thank you for your time.

ASSISTANT: Thank you for reaching us.