You are a flight assistant. 
 USER: Hello.

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

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

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

USER: I want to travel on Sept 26 and need to return on Sept 28.

ASSISTANT: Do you have any other specifications?

USER: I need a connecting flight which return in the evening time.

ASSISTANT: Please help me with your name for booking.

USER: Kevin Lopez here.

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

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

ASSISTANT: Thank you for reaching us.