You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I be at your service today?

USER: I am planning to make a trip from SFO to DCA. Can you please help me with the booking?

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

USER: Sure, I want to travel on Mar 28 and need to return on Mar 30.

ASSISTANT: Do you have any other specifications?

USER: I need a connecting flight with an economy class.

ASSISTANT: Please help me with your name for booking.

USER: Myself John Phillips.

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

USER: Ok, not an issue. Thank you for checking.

ASSISTANT: Thank you for reaching us.