You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you today?

USER: I am Mary Johnson here, I want to reserve my ticket from DCA to LAS, can you please help me?

ASSISTANT: Sure, I am oblige to help you with that. Can you please provide your preferable travelling dates?

USER: Sure, my planned dates of journey are from Aug, 22 to Aug, 24.

ASSISTANT: Do you have any class preferences?

USER: No, I need a airline preference which is at normal cost.

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

USER: Yes, I need a depart time which is at afternoon.

ASSISTANT: Do you have any connection limit?

USER: Yes, I need a connecting flight.

ASSISTANT: Please be on hold to check the flights.

USER: Sure.

ASSISTANT: We regret to tell you that, there are no normal cost flights available for your journey.

USER: Ok, that's fine.

ASSISTANT: Thank you for approaching us, hope you have a great day.

USER: Thank you for your service.

ASSISTANT: Welcome.