Sendkeys is not working everytime, most time it fails

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C#

Hi all,
I am trying to send some key strokes to another running application after activating it. I used notepad for example. But sometimes it works and most of times not. Following is the code I am using. Please anybody findout what is wrong in the code. If it can not be corrected please redirect me to some other nice ways to send keystrokes to other applications.

Thanks in advance
Ismail

Here is the code:
//////////////////////////

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;


namespace send
{
    public partial class Form1 : Form
    {

        [DllImportAttribute("User32.dll")]
        private static extern int FindWindow(String ClassName, String WindowName);


        [DllImportAttribute("User32.dll")]
        private static extern IntPtr SetForegroundWindow(int hWnd);

        [DllImport("user32.dll")]
        static extern bool SetForegroundWindow(IntPtr hWnd);


        public Form1()
        {
            InitializeComponent();
        }


        private void button2_Click(object sender, EventArgs e)
        {

            int hWnd = FindWindow(null, "New Text Document.txt - Notepad");
            if (hWnd > 0)
            {
                SetForegroundWindow(hWnd);
                SendKeys.Send("{TAB}");

                SendKeys.Send("{TAB}");
                SendKeys.Send("TABBBBBBBBBBBBBBB");
            }
            else
            {
                MessageBox.Show("Window Not Found!");
            }


        }


    }
}

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