$watching = "path to watching dir + fileextention to watch\*.pdf*"
$open = "path to exe to open"
FileChangeDir ("path to watching dir")

$timetowatch = 3 * 1000
$timestamp = TimerInit()

While 1
    If TimerDiff($timestamp) >= $timetowatch Then
        $check = FileFindFirstFile($watching)
        If $check <> -1 Then
            While 1
                $file = FileFindNextFile($check)
                If @error Then ExitLoop
                ConsoleWrite ($open)
                $path = ($open &" "& $file)
                ConsoleWrite ($path)
                run ($path)
                sleep (3000)
                FileDelete($file)
            WEnd
        EndIf
        $timestamp = TimerInit()
    EndIf
    Sleep (20)
WEnd