CollectionBase, PictureBox, Panel Derived Controls - Link Problem

Question

My (big) problem, pls help: 2 derived controls and one from CollectionBase: 1) public class ChartGrid : System.Windows.Forms.PictureBox public ChartGrid(Point[] intCol) {...} private void DrawSurface(object sender, PaintEventArgs p) {...} //array of ChartGrid... 2) public class ChartGridArray : System.Collections.CollectionBase public ChartGrid1 AddNewChartGrid(Point[] intValue) { ChartGrid1 nextChart = new ChartGrid1(intValue); ... this.List.Add(nextChart); ownerPanel.Controls.Add(nextChart); //add this control on a Panel ... return nextChart; } public ChartGrid1 this [int Index] { get { return (ChartGrid1) this.List[Index]; } } 3) public class ChartGridPanel1 : System.Windows.Forms.Panel public ChartGridPanel1(double[][] mtrxData, int nrLines, int nrCol) { ... ChartGridArray arrGrafic = new ChartGridArray(this); ... for (int j=0;j