private void TimePlot_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                CurrentMoveOp = TentativeOp;
                if (CurrentMoveOp == MoveOp.resetScale)
                {
                    AutoScaleRequested = true;
                }
                if (CurrentMoveOp == MoveOp.goToZero)
                {
                    if (TimeStamps.Count == 0)
                    {
                        xOffsetG = DrawPlotArea.Width;
                    }
                    else
                    {
                        xOffsetG = DrawPlotArea.Width - TimeStamps.Max() * XPPU;
                    }
                    needsRefresh = true;
                }
                if (CurrentMoveOp == MoveOp.xyPan)
                {
                    Cursor = Cursors.NoMove2D;
                }
                else if (CurrentMoveOp == MoveOp.yZoom)
                {
                    Cursor = Cursors.NoMove2D;
                }


                GAtMouseDown = e.Location;
                VAtMouseDown = GtoV(e.Location);
            }
            else if (e.Button == MouseButtons.Right)
            {
                if (TentativeOp == MoveOp.selectSeries)
                {
                    ContextMenuStrip         = HoverOver.ContextMenuStrip;
                    ContextMenuStrip.Closed += ContextMenuStrip_Closed;
                    MenuStripIsShowing       = HoverOver;
                }
                else if (TentativeOp == MoveOp.yZoom)
                {
                    ContextMenuStrip = yScaleConextMenuStrip;
                }
                else
                {
                    ContextMenuStrip_bkp = ContextMenuStrip;
                    ContextMenuStrip     = null;
                }
            }
            MouseDownAt = LastMouse;
        }