public class SlidePanel : System.Web.UI.WebControls.WebControl
{
	 /*описание свойств, методов и т.д.*/ 
	
	protected override void Render(HtmlTextWriter output)
	{	
		output.Write.............	
	}
}

	public class SlidePanels: ArrayList {......}

[ToolboxData("<{0}:SMControl runat=server></{0}:SMControl>")]
public class SMControl : System.Web.UI.WebControls.WebControl
{
	private SlidePanels parrentList = new SlidePanels();
	...........................

	public SlidePanels Items
	{
		get {return parrentList;}
		set {parrentList = value;}
	}
	..........................
	protected override ??????

}