private void selectGraphsToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (GraphPropertiesForm == null)
            {
                GraphPropertiesForm = new PlotterGraphSelectCurvesForm();
            }

            GraphPropertiesForm.GraphPanel = this.gPane;
            GraphPropertiesForm.Show();
            //  GraphPropertiesForm.BringToFront();
        }
        private void selectGraphsToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (GraphPropertiesForm == null)
            {
                GraphPropertiesForm = new PlotterGraphSelectCurvesForm();
            }

            GraphPropertiesForm.GraphPanel = this.gPane;
            GraphPropertiesForm.Show();
              //  GraphPropertiesForm.BringToFront();
        }