procedure TFrmMain.ImageEnView1MouseDown ( Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer );
begin
  ...
  if ( PageControl2.ActivePage = DrawTab2 ) and PaintPoint.Down then
  begin
    // Paint Point
    with ImageENView1 do
    begin
      Proc.SaveUndo ( ieuImage );
      X := XScr2Bmp ( X );
      Y := YScr2Bmp ( Y );
      fLastPointX := X;
      fLastPointY := Y;
      Transparency := ( ( StrToInt ( Opacity1.Text ) * 255 ) div 100 );
      IEBitmap.Canvas.Pixels [ X, Y ] := PaintColor.Color;
      IEBitmap.Alpha [ X, Y ] := Transparency;
      Update;
    end;
    UpdateUndoMenu;
  end
  ...
end;

procedure TFrmMain.ImageEnView1MouseMove ( Sender: TObject; Shift: TShiftState; X, Y: Integer );
begin
  if ( PageControl2.ActivePage = DrawTab2 ) and PaintPoint.Down and ImageEnView1.MouseCapture then
  begin
    // Paint Point
    with ImageENView1 do
    begin
      X := XScr2Bmp ( X );
      Y := YScr2Bmp ( Y );
      Transparency := ( ( StrToInt ( Opacity1.Text ) * 255 ) div 100 );

      if chkContinuous.checked then
      begin
        IEBitmap.Canvas.Pen.Color := PaintColor.Color;
        IEBitmap.Canvas.MoveTo( X, Y ) ;
        IEBitmap.Canvas.LineTo( fLastPointX, fLastPointY );

        // HAVE NOT TESTED THIS ALPHA CODE
        IEBitmap.AlphaChannel.CanvasCurrentAlpha := Transparency;
        IEBitmap.AlphaChannel.Canvas.MoveTo( X, Y ) ;
        IEBitmap.AlphaChannel.Canvas.LineTo( fLastPointX, fLastPointY );
      end
      else
      begin
        IEBitmap.Canvas.Pixels [ X, Y ] := PaintColor.Color;
        IEBitmap.Alpha [ X, Y ] := Transparency;
      end;

      fLastPointX := X;
      fLastPointY := Y;
      Update;
    end;
  end
  ...
end;