message box show in asp.net

using System;

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.Collections;

using System.Collections.Generic;

/// <summary>

/// Summary description for MessageBox

/// </summary>

public class MessageBox

{

    // Lets keep the message coming from all the pages here

    static Dictionary<Page, Queue> pageTable = null;

   

    static MessageBox()

    {

        // Create the store

        pageTable = new Dictionary<Page, Queue>();

    }

    public static void Show(string str)

    {

        // Lets find out what page is sending the request

        Page page = HttpContext.Current.Handler as Page;

        // If a valid page is found

        if (page != null)

        {

            // Check if this page is requesing message show for the first time

            if (pageTable.ContainsKey(page) == false)

            {

                // Lets create a message queue dedicated for this page.

                pageTable.Add(page, new Queue());

            }

            // Let us add messages of this to the queue now

            pageTable[page].Enqueue(str);

            // Now let put a hook on the page unload where we will show our message

            page.Unload += new EventHandler(page_Unload);

        }       

    }

    static void page_Unload(object sender, EventArgs e)

    {

        // Lets find out which page is getting unloaded

        Page page = sender as Page;

        // If a valid page is founf

        if (page != null)

        {

            // Extract the messages for this page and push them to client side

            HttpContext.Current.Response.Write("<script>alert('" + pageTable[page].Dequeue() + "');</script>");

        }

    }

}

//Pokemon exception handling

           // MessageBox.Show("Exception has occured: " + //ex.Message);