[philmckrakin]

Set the timer to 1 second (1000) and have the repeat set to true, then inside the timer func you want to do
if (!isplayerinrangeofpoint(playerid, x, y, z, range))
{
Ban();
}

and be sure to use killtimer when the player leaves the cell/jail
one more note you will need to use settimerex for this aswell.

but in the end I recomend you finding an anti cheat because there are better (but more complex) ways to do it

Hope this puts you on your path xD

Happy scripting /phil