You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am looking for a flight from DCA to OAK, can you please help me in booking?

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

USER: I will start my journey on Jan 30 and return back on Feb 01.

ASSISTANT: Do you have any other specifications?

USER: I want to depart in afternoon.

ASSISTANT: Please help me with your name for booking.

USER: My name is Rachel Moore.

ASSISTANT: Sorry for this inconvenience, I could not find any flight with your requirements.

USER: That's ok, thank you for checking.