zed그래프 클릭하면 빨간 선 나오기

  PointPairList userClickrList = new PointPairList();

        LineItem userClickCurve = new LineItem("userClickCurve");

        private void z2_MouseClick(object sender, MouseEventArgs e)  // ZedGraph 클릭시 빨간선 나옴. 

        {

            // Create an instance of Graph Pane

            GraphPane myPane = z2.GraphPane;

            // x & y variables to store the axis values

            double xVal;

            double yVal;

            // Clear the previous values if any

            userClickrList.Clear();

            myPane.Legend.IsVisible = false;

            // Use the current mouse locations to get the corresponding 

            // X & Y CO-Ordinates

            myPane.ReverseTransform(e.Location, out xVal, out yVal);

            // Create a list using the above x & y values

            userClickrList.Add(xVal, myPane.YAxis.Scale.Max);

            userClickrList.Add(xVal, myPane.YAxis.Scale.Min);

            // Add a curve

            userClickCurve = myPane.AddCurve(" ", userClickrList, Color.Red, SymbolType.None);

            z2.Refresh();

        }