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 FileTokenNotWork
{
    public partial class Form1 : Form
    {
        FileStream fs = null;
        int count = 0;
        public Form1()
        {
            InitializeComponent();
        }

        private void btnUpdate_Click(object sender, EventArgs e)
        {
            OpenFileDialog ofd = new OpenFileDialog();
            ofd.ShowDialog();
            filedirtectory.Text = ofd.FileName;

        }

        private void button1_Click(object sender, EventArgs e)
        {
            count++;
            if (count > 1)
            {
                MessageBox.Show("Do not do it again.","Warning",MessageBoxButtons.OK,MessageBoxIcon.Warning);
                return;
            }
            try
            {
                if (string.IsNullOrEmpty(filedirtectory.Text))
                {
                    MessageBox.Show("Not have the file", "Warning", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    count--;
                    return;
                }
                fs = new FileStream(filedirtectory.Text, FileMode.Open, FileAccess.Read, FileShare.None);
            }
            catch (Exception)
            {
                fs.Close();
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            count--;
            fs.Close();
        }
    }
}

?

namespace FileTokenNotWork
{
    partial class Form1
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.btnUpdate = new System.Windows.Forms.Button();
            this.openFileDialog = new System.Windows.Forms.OpenFileDialog();
            this.filedirtectory = new System.Windows.Forms.TextBox();
            this.groupBox1 = new System.Windows.Forms.GroupBox();
            this.groupBox2 = new System.Windows.Forms.GroupBox();
            this.button1 = new System.Windows.Forms.Button();
            this.button2 = new System.Windows.Forms.Button();
            this.groupBox1.SuspendLayout();
            this.groupBox2.SuspendLayout();
            this.SuspendLayout();
            // 
            // btnUpdate
            // 
            this.btnUpdate.Location = new System.Drawing.Point(175, 20);
            this.btnUpdate.Name = "btnUpdate";
            this.btnUpdate.Size = new System.Drawing.Size(75, 23);
            this.btnUpdate.TabIndex = 0;
            this.btnUpdate.Text = "submit";
            this.btnUpdate.UseVisualStyleBackColor = true;
            this.btnUpdate.Click += new System.EventHandler(this.btnUpdate_Click);
            // 
            // openFileDialog
            // 
            this.openFileDialog.FileName = "openFileDialog";
            // 
            // filedirtectory
            // 
            this.filedirtectory.Location = new System.Drawing.Point(18, 22);
            this.filedirtectory.Name = "file