You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I am Donald Davis. Can you please book a flight ticket from DCA to PHX?

ASSISTANT: Sure, let me know your journey dates?

USER: I will start on Aug 1 and need to return on Aug 3.

ASSISTANT: Do you need any halt in between your journey?

USER: Yes, I need a single connection.

ASSISTANT: Ok, Is there any class preference?

USER: I am comfortable with of the class.

ASSISTANT: Do you have any price limit?

USER: The price limit is 500.

ASSISTANT: Please hold on a minute, I will check the best flight for you.

USER: Sure.

ASSISTANT: Sorry to inform that, there is no flights found on your dates.

USER: No problem, thanks for the information.

ASSISTANT: Thanks for reaching us, have a nice day.