Please bear with the length of this question.  I just think that I need to explain my situation clearly so that people will understand exactly what I'm hoping to find.

I have three children, two of whom have autism-spectrum disorders and ADD.  They love their computer time, and would spend all day with their noses in the monitor if I would let them.

We have determined to limit them to 2 hours per day during the Summer months.  But they keep "losing track of the time," or "not hearing the timer go off," or "forgetting to set the timer," etc.  We tried using Stickies (www.zhornsoftware.co.uk) and setting them to pop up on the screen when their time was over, but on certain graphics-intensive games, the sticky won't come to the front. 

Since all three boys like to divide their two hours into 4 half-hour chunks, you can appreciate that it's difficult for me to keep on top of it all.

I'm really hoping to find a program that can do the following:

-Require each boy to enter his own password to access the computer
-Allow parents to set how much time each password can access the computer per day
-When time is up, divert the child to some sort of screen, which is all they will see for the rest of the day
-Automatically reset the timer every day for each child
-Allow the child to "log off" to stop his timer whenever he leaves the computer
-Auto logoff for that password if unused for a set period (for when the child forgets to log off)

Does anyone know of any program that can meet that need?

Thanks,
Betsy

Thanks!  You guys are awesome!