Shutdown Computer

Hello,

I have created a script that shuts down the computer. It is first checked whether the Explorer.exe process runs when yes, a message appears that the PC is shut down. Unfortunately, the script now waiting for input.
What do I need to adjust so that from then runs a timer? Can you help me?

Here ist the script:

# Parameter
$Counter = "1"
$TimeLeft = "5"

$wshell = New-Object -ComObject Wscript.Shell

$process = Get-WmiObject -Query "Select * from Win32_Process Where Name = 'explorer.exe'"

if ($prcess.Count -eq 0)
{
 Stop-Computer
}

while ($Counter -lt 11)
{
 $Return = $wshell.Popup("Your computer will shutdown in " + $TimeLeft + " minutes. Click OK to cancel the shutdown.",0,"Shutdown Pending",32)

 If ($Return -eq 1)
 {
  $wshell.Popup("Shutdown has been cancelled!", 6,"SHUTDOWN CANCELLED", 0)
  exit
 }
 $TimeLeft = $TimeLeft - .5
 $Counter = $Counter + 1
}

Stop-Computer