Connected user warning

Hey!
Long time no see :wave:
Here is my problem: I want to have a way to popup a warning if there is a user conected to my computer!
If you go in XP to Computer Management Console you see a section Shared Folders and in it a section called Sessions. If there is a user connected to the computer he will appear in this list. The thing is I don't wanna spend my day pressing the refresh button so I wanna make a popup warning when someone is connecting. Can you give me any advice where to start?

Thank you!