AutoIt countdown timer

So i've been playing around with AutoIt recently. Its a great little piece of software for writting automated programs. Its like a cross between C and python. But the best part about it is that as its comunity based anyone can write their own functions for it and add them to the site. Great!

Anyway, we've selected a few open access computers that are going to be used for electronic submission only. The higher manangement wanted a piece of software that would instruct the student logged on that they would have a maximum of 15 minutes on the PC, and then get logged off. After a bit of discussion I managed to get them to accept giving the students a warning that their time was up and then the counter would count backwards in big red writting.

So this is the code

#include <GUIConstants.au3>
#include <WindowsConstants.au3>
#include <StaticConstants.au3>
#include <EditConstants.au3>

$ms = 900250 ;This is the time in milliseconds Adjust as needed
$timer = TimerInit()
traysetstate(2)
$labeltext = "This computer is primarily for electronic submission. You will be automatically logged off after 15 minutes"
GUICreate("Electronic Submission", 350, 330, -1, -1, $WS_DLGFRAME, $WS_EX_TOPMOST)
$Label = GUICtrlCreateLabel($labeltext, 10, 10, 330, 200, $SS_CENTER)
GUICtrlSetFont(-1, 18, 400, $labeltext)
$Input = GUICtrlCreateInput("", 125, 150, 90, 40, BitOr($SS_CENTER, $ES_READONLY, $WS_CLIPCHILDREN))
GUICtrlSetFont(-1, 18, 400)
GUISetState (@SW_SHOW)
WinSetTrans("Electronic Submission","", 127)
While (TimerDiff($timer) < $ms)
   $seconds = TimerDiff($timer)/1000
   $diff = $seconds - ($ms/1000);
   $minutes = Int($diff / 60)
   $secondsRem = $diff - ($minutes * 60)
   $minutes = $minutes * -1
   $secondsRem = $secondsRem * -1
   $time = StringFormat("%02d", $minutes) & ":" & StringFormat("%02d", $secondsRem)
   GUICtrlSetData($Input, $time)
   WEnd
 
   Global $reply = MsgBox(1, "TIMES UP", &@UserName " you have had 15 minutes on this computer. If someone is waiting please let them use it. CLICK OK TO LOG OFF",30)
   If $reply = 1  then run("shutdown.exe -l")
  
   $Input = GUICtrlCreateInput("", 25, 125, 300, 100, BitOr($SS_CENTER, $ES_READONLY, $WS_CLIPCHILDREN))
   GUICtrlSetColor(-1, 0xff0000)
   GUICtrlSetFont(-1, 50, 400)
  
   While (TimerDiff($timer) > $ms)
   $seconds = TimerDiff($timer)/1000
   $diff = $seconds - ($ms/1000)
   $minutes = Int($diff / 60)
   $secondsRem = $diff - ($minutes * 60)
   $minutes = $minutes * -1
   $secondsRem = $secondsRem * -1
   $time = StringFormat("%02d", $minutes) & ":" & StringFormat("%02d", $secondsRem)
   GUICtrlSetData($Input, $time)
   WEnd
   run("shutdown.exe -l")

Its not the best code, but im just learning it. feel free to adjust and use it for yourselves.