public List<string> SearchDirectory(string FileName, string DirectoryName)
        {
            //Declare a List of Strings for Returning File Names
            List<string> strFileNames = new List<string>();
            try
            {
                //Get the Directory Info using Directory Name
                DirectoryInfo dirInfor = new DirectoryInfo(DirectoryName);
                // Get all files whose names starts with FileName Passed 
                FileInfo[] filesInfo = dirInfor.GetFiles(FileName + 
                    "*", SearchOption.TopDirectoryOnly);
                //Loop through all the files found and add to 
                //List and return them
                foreach (FileInfo fi in filesInfo)
                {
                    strFileNames.Add(fi.FullName);
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }

            return strFileNames;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            //Open the folder Browser Dialog for Selecting the directory
            // and search text from a Text box
            folderBrowserDialog1.ShowDialog();
            //Shows the no of files found the directory
            MessageBox.Show(SearchDirectory(textBox1.Text,
                folderBrowserDialog1.SelectedPath).Count.ToString()
                + " Files found");
        }