namespace Quxian
{
    public partial class FormQuxian : Form
    {
        Random ran = new Random();
        
        PointPairList list = new PointPairList();
       
        LineItem myCurve;
       
        public FormQuxian()
        {
            InitializeComponent();
        }
        private void timer1_Tick(object sender, EventArgs e)
        {
            zedGraphControl1.GraphPane.XAxis.Scale.MaxAuto = true;            double x = (double)new XDate(DateTime.Now);            double y = ran.NextDouble();            list.Add(x, y);
      
            this.zedGraphControl1.AxisChange();            this.zedGraphControl1.Refresh();
            if (list.Count >= 40)
            {
                list.RemoveAt(0);
            }
           
        }
            private void button3_Click(object sender, EventArgs e)
        {            GraphPane myPane = zedGraphControl1.GraphPane;
           
            myPane.CurveList.Clear();
            this.zedGraphControl1.AxisChange();
            this.zedGraphControl1.Refresh();
            this.zedGraphControl1.GraphPane.Title.Text = "实时浓度曲线图";
            this.zedGraphControl1.GraphPane.XAxis.Title.Text = "时间";            this.zedGraphControl1.GraphPane.YAxis.Title.Text = "浓度(mg/L)";            this.zedGraphControl1.GraphPane.XAxis.Type = ZedGraph.AxisType.DateAsOrdinal;            DateTime dt = DateTime.Now;
            
            myCurve = zedGraphControl1.GraphPane.AddCurve("My Curve", list, Color.Red, SymbolType.None);
            this.zedGraphControl1.AxisChange();
            this.zedGraphControl1.Refresh();        }
 }
}我用以上代码实现了zedGraph曲线图的绘制,但是我要在里面画两条曲线,用不同的颜色表示,请问下该如何添加,本人C#菜鸟,多谢各位大侠帮忙!!