comparing two ms word, ms excel, powerpoint files

Question

I want to compare two files..  so i m using this code..  but i m getting wrong ans while comparing.. even two ms word files that i hv created are totally same.. still i m nt getting correct output..  thank you.. 

 

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using System.IO;

namespace WindowsFormsApplication3

{

public partial class Form1 : Form

{

public Form1()

{

InitializeComponent();

}

private bool filecompare(string file1, string file2)

{

int file1byte;

int file2byte;

FileStream fs1;

FileStream fs2;

if (file1 == file2)

{

return true;

}

fs1 = new FileStream(file1, FileMode.Open);

fs2 = new FileStream(file2, FileMode.Open);

if (fs1.Length == fs2.Length)

{

fs1.Close();

fs2.Close();

return false;

}

do

{

file1byte = fs1.ReadByte();

file2byte = fs2.ReadByte();

}

while ((file1byte == file2byte) || (file1byte != -1));

fs1.Close();

fs2.Close();

return ((file1byte - file2byte) == 0);

}

private void button1_Click(object sender, EventArgs e)

{

if (filecompare(this.textBox1.Text, this.textBox2.Text))

{

MessageBox.Show("File are equals ");

}

else

{

MessageBox.Show("files are not equal");

}

}

}

}