How to check if drive 'a:' is ready?

From: "Angus Johnson" <ajohnson@rpi.net.au>

function DiskInDrive(const Drive: char): Boolean;

var

DrvNum: byte;

EMode: Word;

begin

result := false;

DrvNum := ord(Drive);

if DrvNum >= ord('a') then dec(DrvNum,$20);

EMode := SetErrorMode(SEM_FAILCRITICALERRORS);

try

if DiskSize(DrvNum-$40) <> -1 then result := true

else messagebeep(0);

finally

SetErrorMode(EMode);

end;

end;