procedure TForm1.deletedirectory(dir: string);
var
  sh: SHFILEOPSTRUCT;
  st: string;
  sr: tsearchrec;
  pst: pchar;
begin
  if findfirst(dir, faDirectory, sr) = 0 then
  begin
    //added by me
    dir := longtoshortfilename(dir);
    //original code
    sh.Wnd := Form1.handle;
    sh.wFunc := FO_DELETE;
    Pst := StrAlloc(Length(dir {sr.Name}) + 1);
    StrPLCopy(Pst, dir {sr.Name}, Length(dir {sr.Name}) + 1);
    sh.pFrom := pst;
    sh.pTo := nil;
    sh.fFlags := FOF_NOCONFIRMATION or FOF_SILENT;
    sh.hNameMappings := nil;
    sh.lpszProgressTitle := nil;
    SHFileOperation(sh);
    StrDispose(Pst);
  end;
  findclose(sr);
end;