float sv = (float)testPnl1.VerticalScroll.Value / (float)testPnl1.VerticalScroll.Maximum;
float sh = (float)testPnl1.HorizontalScroll.Value/(float)testPnl1.HorizontalScroll.Maximum;
ImageWidth += zoom;
Pnl.AutoScrollPosition = new Point((int)(Pnl.HorizontalScroll.Maximum * sh), (int)(Pnl.VerticalScroll.Maximum * sv));