Below Class can be used to display messages to the end user.(In Web applications).

public class clsMessage
    {
        protected static Hashtable handlerPages = new Hashtable();
        private clsMessage()
        {
        }

        public static void Show(string Message)
        {
            if (!(handlerPages.Contains(HttpContext.Current.Handler)))
            {
                Page currentPage = (Page)HttpContext.Current.Handler;
                if (!((currentPage == null)))
                {
                    Queue messageQueue = new Queue();
                    messageQueue.Enqueue(Message);
                    handlerPages.Add(HttpContext.Current.Handler, messageQueue);
                    currentPage.Unload += new EventHandler(CurrentPageUnload);
                }
            }
            else
            {
                Queue queue = ((Queue)(handlerPages[HttpContext.Current.Handler]));
                queue.Enqueue(Message);
            }
        }

        private static void CurrentPageUnload(object sender, EventArgs e)
        {

            Queue queue = ((Queue)(handlerPages[HttpContext.Current.Handler]));
            if (queue != null)
            {
                StringBuilder builder = new StringBuilder();
                int iMsgCount = queue.Count;
                builder.Append("<script language=’javascript’>");
                string sMsg;
                while ((iMsgCount > 0))
                {

                    iMsgCount = iMsgCount – 1;
                    sMsg = System.Convert.ToString(queue.Dequeue());
                    sMsg = sMsg.Replace("\"", "’");
                    builder.Append("alert( \"" + sMsg + "\" );");
                }
                builder.Append("</script>");
                handlerPages.Remove(HttpContext.Current.Handler);
                HttpContext.Current.Response.Write(builder.ToString());
            }
        }
    }

Pawan Kumar
Pawankkmr@hotmail.com