Shared Addin in C Sharp

Question

I'm totally new in Addin in .net 2010. I have searched a code which is working fine to just show the messagebox in Microsoft office application thorough a custom button. Please help me that how can I write some text into Office document through this button and call my own popup form.

My code is this:

using Microsoft.Office.Core;

using System;
using System.Collections.Generic;

using System.Text;

using Word = Microsoft.Office.Interop.Word;
using Office = Microsoft.Office.Core;
using Microsoft.Office.Tools.Word;
using Microsoft.Office.Interop.Word;


namespace HadithAddin1
{
 using System;
 using Extensibility;
    using System.Reflection;
 using System.Runtime.InteropServices;

 #region Read me for Add-in installation and setup information.
 // When run, the Add-in wizard prepared the registry for the Add-in.
 // At a later time, if the Add-in becomes unavailable for reasons such as:
 //   1) You moved this project to a computer other than which is was originally created on.
 //   2) You chose 'Yes' when presented with a message asking if you wish to remove the Add-in.
 //   3) Registry corruption.
 // you will need to re-register the Add-in by building the HadithAddin1Setup project, 
 // right click the project in the Solution Explorer, then choose install.
 #endregion

 /// <summary>
 ///   The object for implementing an Add-in.
 /// </summary>
 /// <seealso class='IDTExtensibility2' />
 [GuidAttribute("15CC1BC6-7AC7-42B2-8C11-325403243263"), ProgId("HadithAddin1.Connect")]
 public class Connect : Object, Extensibility.IDTExtensibility2
 {
  /// <summary>
  ///  Implements the constructor for the Add-in object.
  ///  Place your initialization code within this method.
  /// </summary>
        public void OnConnection(object application, Extensibility.ext_ConnectMode connectMode, object addInInst, ref System.Array custom)
        {
            applicationObject = application;
            addInInstance = addInInst;

            if (connectMode != Extensibility.ext_ConnectMode.ext_cm_Startup)
            {
                OnStartupComplete(ref custom);
            }

        }

        public void OnDisconnection(Extensibility.ext_DisconnectMode disconnectMode, ref System.Array custom)
        {
            if (disconnectMode != Extensibility.ext_DisconnectMode.ext_dm_HostShutdown)
            {
                OnBeginShutdown(ref custom);
            }
            applicationObject = null;
        }


        public void OnAddInsUpdate(ref System.Array custom)
        {
        }

        public void OnStartupComplete(ref System.Array custom)
        {
            CommandBars oCommandBars;
            CommandBar oStandardBar;

            try
            {
                oCommandBars = (CommandBars)applicationObject.GetType().InvokeMember("CommandBars", BindingFlags.GetProperty, null, applicationObject, null);
            }
            catch (Exception)
            {
                // Outlook has the CommandBars collection on the Explorer object.
                object oActiveExplorer;
                oActiveExplorer = applicationObject.GetType().InvokeMember("ActiveExplorer", BindingFlags.GetProperty, null, applicationObject, null);
                oCommandBars = (CommandBars)oActiveExplorer.GetType().InvokeMember("CommandBars", BindingFlags.GetProperty, null, oActiveExplorer, null);

            }

            // Set up a custom button on the "Standard" commandbar.
            try
            {
                oStandardBar = oCommandBars["Standard"];
            }
            catch (Exception)
            {
                // Access names its main toolbar Database.
                oStandardBar = oCommandBars["Database"];
            }

            // In case the button was not deleted, use the exiting one.
            try
            {
                MyButton = (CommandBarButton)oStandardBar.Controls["My Custom Button"];
            }
            catch (Exception)
            {
                object omissing = System.Reflection.Missing.Value;
                MyButton = (CommandBarButton)oStandardBar.Controls.Add(1, omissing, omissing, omissing, omissing);
                MyButton.Caption = "My Custom Button";
                MyButton.Style = MsoButtonStyle.msoButtonCaption;
            }

            // The following items are optional, but recommended. 
            //The Tag property lets you quickly find the control 
            //and helps MSO keep track of it when more than
            //one application window is visible. The property is required
            //by some Office applications and should be provided.
            MyButton.Tag = "My Custom Button";

            // The OnAction property is optional but recommended. 
            //It should be set to the ProgID of the add-in, so that if
            //the add-in is not loaded when a user presses the button,
            //MSO loads the add-in automatically and then raises
            //the Click event for the add-in to handle. 
            MyButton.OnAction = "!<MyCOMAddin.Connect>";

            MyButton.Visible = true;
            MyButton.Click += new Microsoft.Office.Core._CommandBarButtonEvents_ClickEventHandler(this.MyButton_Click);


            object oName = applicationObject.GetType().InvokeMember("Name", BindingFlags.GetProperty, null, applicationObject, null);

            // Display a simple message to show which application you started in.
            System.Windows.Forms.MessageBox.Show("This Addin is loaded by " + oName.ToString(), "MyCOMAddin");


            oStandardBar = null;
            oCommandBars = null;
        }

        public void OnBeginShutdown(ref System.Array custom)
        {
            object omissing = System.Reflection.Missing.Value;
            System.Windows.Forms.MessageBox.Show("MyCOMAddin Add-in is unloading.");
            MyButton.Delete(omissing);
            MyButton = null;
        }

        private void MyButton_Click(CommandBarButton cmdBarbutton, ref bool cancel)
        {
            System.Windows.Forms.MessageBox.Show("MyButton was Clicked", "MyCOMAddin"); 

        }


  private object applicationObject;
  private object addInInstance;
        private CommandBarButton MyButton; 
 }
}