You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Mark Phillips here.

ASSISTANT: How can I help you today?

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

ASSISTANT: Sure, I am at your service to help you.Can you please provide your planned dates?

USER: My travelling dates are from 05/24 to 05/26.

ASSISTANT: Ok, may I know your airport codes please?

USER: My airport codes are from DEN to MSP.

ASSISTANT: Ok, please wait for a moment.

USER: Ok, I will wait.

ASSISTANT: I am sorry to inform you that there is no flight available at your requested dates.

USER: Anyway, thanks for the information.

ASSISTANT: You are welcome, have a nice day.