SetConsole("HIDE");


$first = 1

:top

$devices = "DEIJKLMNOPQRSTUVWXY";
$offset = 1;
$end = "n";

do 

  $drive = SUBSTR($devices, $offset, 1);

  if $drive <> ""

     if exist("$drive:\fog")
	$end = "y";
     endif

     $offset = $offset + 1;
  else
     $end = "y";
  endif

until $end = "y";

if $first = 1
  if $drive = ""
   $selection = MESSAGEBOX(
     "This program requires a CDROM drive. Does it have a CDROM drive?",
        "Focus on Grammar", 36);
   if $selection <> 6
      goto "nodrive";
   endif
  endif
endif

$first = 0

$filename = "fog_b.tbk"
if exist("$drive:\fog\" + "$filename")
   goto "runit"
endif

$filename = "fog_i.tbk"
if exist("$drive:\fog\" + "$filename")
   goto "runit"
endif

$filename = "fog_a.tbk"
if exist("$drive:\fog\" + "$filename")
   goto "runit"
endif

$selection = MESSAGEBOX("Please insert the Focus on Grammar CDROM into the CDROM drive", "Proper CDROM Disk Not Found", 49)

if $selection <> 1
   goto "nodrive"
endif

goto "top"

:runit

GO "$drive:"

CD "FOG"

$selection = MESSAGEBOX("Program load may take about minute. Please be patient", "Focus on Grammar", 64, 30)

run "mtb40run.exe $filename"

goto "exit"

:nodrive

$selection = MESSAGEBOX(
   "Sorry, a CDROM drive and the Focus on Grammar CD is required to use the program. Please contact a sysop or your instructor for help.", 
   "Focus on Grammar", 64)

:exit