6. Application pages

Voila !

Your pages can just do this:

1. Show a MessageBox, in WinForms style ;)

   protected void btn_Action_1_Click(object sender, EventArgs e)
   {
       this.MessageBox.ShowMessage(
           messageBoxKey: "ACTION_1_key",
           message: "Message to user for Action 1",
           messageType: MessageBoxType.Information,
           buttons: MessageBoxButtons.OK);
   }

2. Manage their response (there is a key to identify different actions)

   /// <summary>
   /// Called when [response message box].
   /// </summary>
   /// <param name="sender">The sender.</param>
   /// <param name="e">The <see cref="MessageBoxEventArgs"/> instance containing the event data.</param>
   protected override void OnResponseMessageBox(object sender, MessageBoxEventArgs e)
   {
       //TODO: This is suitable for a table driven method. This is only one example
       this.txt_response.Text = string.Format("MessageBoxKey: {0}. Response: {1}", e.MessageBoxKey, e.Response);
   }