using System;
using Microsoft.VisualBasic; 
using System.Text; 
using System.Collections;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace TestWebMsgApp
{
    public class WebMsgBox 
    { 
        protected static Hashtable handlerPages = new Hashtable();             

        private WebMsgBox() 

        { 

        } 
        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());

            } 

        } 

    }

 

}