ASP.NET User Controls - Notify One Control Of Changes In Other Control

using System;
using System.Diagnostics;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

using ASPNet_App.Controls;

namespace ASPNet_App
{
	/// <summary>
	/// Summary description for BannerAds.
	/// </summary>
	public class BannerAds : System.Web.UI.Page
	{
		protected System.Web.UI.WebControls.Panel BannerDiv;
	
		private void Page_Load(object sender, System.EventArgs e)
		{
			// Put user code to initialize the page here
			//if (!IsPostBack)
			{
				// Load the UserControls into BannerAd div.
				Control bannerControl;
				Control banner;
				try
				{
					bannerControl = LoadControl("Controls/SiteBannerManager.ascx");
					banner = LoadControl("Controls/SiteBanner.ascx");
					if (bannerControl != null)
					{
						((SiteBannerManager)bannerControl).BannerChange += new BannerChangeEventHandler(((SiteBanner)banner).ChangeBannerImage);
					}

					CreateBannerControlTable(bannerControl, banner);
				}
				catch (Exception ex)
				{
					Trace.Write(ex.Message);
				}
			}
		}

		private void CreateBannerControlTable(Control leftCtl, Control rightCtl)
		{
			Table tbl = new Table();
			TableRow row = new TableRow();

			TableCell leftCol = new TableCell();
			TableCell rightCol = new TableCell();

			leftCol.Controls.Add(leftCtl);
			leftCol.HorizontalAlign = HorizontalAlign.Center;
			leftCol.VerticalAlign = VerticalAlign.Top;
			leftCol.Width = 200;

			rightCol.Controls.Add(rightCtl);
			rightCol.HorizontalAlign = HorizontalAlign.Center;
			rightCol.VerticalAlign = VerticalAlign.Top;

			row.Cells.Add(leftCol);
			row.Cells.Add(rightCol);

			tbl.Rows.Add(row);

			BannerDiv.Controls.Add(tbl);
		}
		

		#region Web Form Designer generated code
		override protected void OnInit(EventArgs e)
		{
			//
			// CODEGEN: This call is required by the ASP.NET Web Form Designer.
			//
			InitializeComponent();
			base.OnInit(e);
		}
		
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{    
			this.Load += new System.EventHandler(this.Page_Load);

		}
		#endregion
	}
}