You are a flight assistant. 
 USER: Hi.

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

USER: Help me in booking a flight from DEN to LAX?

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

USER: My travelling dates are June 15 to 17.

ASSISTANT: Do you have any other specifications?

USER: I prefer direct flight and I want to depart in morning.

ASSISTANT: Please help me with your name for booking.

USER: I am Rebecca Harris.

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

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.