[2.0] Updating a specific part of my window (in the paint event)

[Icyculyr]

        private void Form1_Paint(object sender, PaintEventArgs e)
        {
			for (int i = 0; i < currentGrid.GetUpperBound(0); i++)
			{
				for (int k = 0; k < currentGrid.GetUpperBound(1); k++)
				{
					Bitmap bmp = new Bitmap(images[currentGrid[i, k]]);
					e.Graphics.DrawImage(bmp, new Point(k * gridWidth, i * gridHeight));
					bmp.Dispose();
					bmp = null;
				}
			}	
			HighlightTile(e);
		}

when I click, it updates the position that my highlighted tile is at, however I have to call this.Refresh();, and it lags because I am drawing the whole thing again, any way I can refresh 'only' a part of it?