You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you at this time?

USER: I am Debra Brown. As I am a scientist, I want to attend science festival with my students at ATL. Can you help me in booking from LAX?

ASSISTANT: Sure, may I know your departure and arrival travelling dates?

USER: My trip dates are Dec 23 to Dec 25.

ASSISTANT: May I know your specific time preferences?

USER: I need a connecting flight which return in afternoon.

ASSISTANT: Please be on hold for a moment.

USER: Sure.

ASSISTANT: I regret to inform you that no airlines is providing a flight for you on your specific time.

USER: No issue, thank you.

ASSISTANT: You are most welcome.