You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Patrick Hall.

ASSISTANT: How may I aid you today?

USER: Can you help me in booking from ORD to IAD, as there is a business meeting to attend?

ASSISTANT: Sure, I will help you with that. Can you please provide your travelling dates?

USER: My trip dates are Jun 18 to Jun 20.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: Is there any specific timings in your departure and arrival?

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

ASSISTANT: Please be on hold to check the flights.

USER: Sure.

ASSISTANT: We regret to inform you that, there are no flights available for your journey with your required preferences.

USER: No issue, thank you.

ASSISTANT: Thank you for utilizing our services.