type
 TForm1 = class(TForm)
  Label1: TLabel;
  Label2: TLabel;
  Timer1: TTimer;
  procedure Timer1Timer(Sender: TObject);
  procedure FormCreate(Sender: TObject);
 private
  procedure ShowHwndAndClassName(CrPos: TPoint);
 public
end;
var
 Form1: TForm1;
implementation
{$R *.DFM}
procedure TForm1.Timer1Timer(Sender: TObject);
var
 rPos: TPoint;
begin
 if Boolean(GetCursorPos(rPos)) then ShowHwndAndClassName(rPos);
end;
procedure TForm1.ShowHwndAndClassName(CrPos: TPoint);
var
 hWnd: THandle;
 aName: array [0..255] of Char;
begin
 hWnd := WindowFromPoint(CrPos);
 Label1.Caption := 'Handle : ' + IntToStr(hWnd);
 if Boolean(GetClassName(hWnd, aName, 256)) then
  Label2.Caption := 'ClassName : ' + string(aName)
 else
  Label2.Caption := 'ClassName : not found';
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
 Form1.FormStyle := fsStayOn;
 Timer1.Interval := 50;
end;