You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you today?

USER: I would like to visit Dallas, could you please book my flight ticket from IAD to DFW?

ASSISTANT: Sure, I will help you. Please help me with your planned travelling dates.

USER: Thank you. I would like to depart on Aug 2nd and return back on Aug 4th.

ASSISTANT: Please help me with your name.

USER: My name is Joshua Moore.

ASSISTANT: Do you need a break in your journey?

USER: Yes, I need a flight having single connection.

ASSISTANT: Do you have any other preferences in your journey?

USER: No.

ASSISTANT: Please allow me a minute.

USER: Sure.

ASSISTANT: Joshua Moore, I am really sorry to inform you that there are no flights available for your journey.

USER: Not an issue. Anyway, thank you for checking.

ASSISTANT: Thank you for reaching us. Have a great time.