You are a flight assistant. 
 USER: Hello. Barbara Carter here.

ASSISTANT: Hello, how may I render you today?

USER: I would like to visit Phoenix for a business trip, can you please reserve a flight ticket from DCA to PHX?

ASSISTANT: Sure, we are glad to help you.

USER: Thank you.

ASSISTANT: Can you please let me know your depart and arrival dates of the journey?

USER: My departure is on 08/18 and please book my return ticket also on 08/20.

ASSISTANT: How much you can spend for airfare?

USER: I can afford up to 5000.

ASSISTANT: Ok, please wait for a while.

USER: Sure, take your time.

ASSISTANT: We found a connecting flight with Delta airlines, flight number 1016 and the fare of 100. Shall I proceed?

USER: That's fine, you can proceed with booking now.

ASSISTANT: Your ticket has been reserved in economy class.

USER: Thank you for your great help in my ticket booking.

ASSISTANT: Thank you for reaching us.

USER: Welcome.