function GetShortName (const FileName: string): string;
var aTmp: array[0..255] of char;
begin
  if not FileExists (FileName) then
    Result := ''
  else if GetShortPathName (PChar (FileName), aTmp, Sizeof (aTmp) - 1) = 0
  then
    Result:= FileName
  else
    Result:= StrPas (aTmp);
end;

function GetShortName(sLongName: string): string; 
var 
  sShortName:    string; 
  nShortNameLen: Integer; 
begin 
  SetLength(sShortName, MAX_PATH); 
  nShortNameLen := GetShortPathName(PChar(sLongName), PChar(sShortName), MAX_PATH - 1); 
  if (0 = nShortNameLen) then 
  begin 
  showmessage('Error!'); 
  end; 
  SetLength(sShortName, nShortNameLen); 
  Result := sShortName; 
end;

uses SysUtils;
// berikut cuplikannya
function ExtractShortPathName(const FileName: string): string;
var
  Buffer: array of Char;
begin
  SetString(Result, Buffer,
    GetShortPathName(PChar(FileName), Buffer, SizeOf(Buffer)));
end;