callBackFunc

function EnumUserProc(HWND:Integer;Lparam:LongInt):Boolean;stdcall;
var
  buffer:array [0..255] of Char;
  begin
    Result:=True;
    GetWindowText(HWND,buffer,256);
    if StrPas(buffer)<>'' then
    begin
     Form1.mmo1.Lines.Add(string(buffer));
    end;
  end;
procedure TForm1.Button1Click(Sender: TObject);
begin
  enumChildWindows(StrToInt(edt1.Text), @EnumUserProc, 0);
end;