You are a flight assistant. 
 USER: Hello. Steven Brown here.

ASSISTANT: Hello, do you need any help from us?

USER: I want to attend a Seminar in Dallas. Can you please help me for booking the flight ticket?

ASSISTANT: Sure, I am beatific to help you. May I know on what dates you need booking?

USER: My travelling dates are from 11/17 to 11/19.

ASSISTANT: Ok, could I have your destination and origin airport codes?

USER: My airport codes are from MSP to DFW.

ASSISTANT: Sorry, all flight tickets are sold out on your requested travelling dates.

USER: Anyway, thanks for the information.

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