Delete Directory with non empty subdirectory and files

function DeleteDirWithFiles(dir: string): boolean;
var
    sl: TStringList;
    i,c: integer;
begin
    result := True;
    sl := TStringList.Create;
    sl.Text := GetFilesList(dir);

    // delete all files
    c := sl.Count-1;
    for i := 0 to c do
        if not DeleteFile(sl[i]) then
        begin
            ShowMessage('Can''t remove file '+sl[i]);
            result := False;
        end;

    // delete directiries
    sl.Text := GetDirectories(dir);
    c := sl.Count-1;
    for i := c downto 0 do
        if not RemoveDir(sl[i]) then
        begin
            ShowMessage('Can''t remove dirercory '+sl[i]);
            result := False;
        end;

    // delete main directory
    RemoveDir(dir);
    sl.Free;
end;


// how to use function DeleteDirWithFiles
procedure Form1_Button4_OnClick (Sender: string; var Cancel: boolean);
var
    sDir: string;
begin
    sDir := 'd:\folder';

    if not DeleteDirWithFiles(sDir) then
        ShowMessage('Can''t remove directory');
end;