c# ile cdrom acma kapama

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.Runtime.InteropServices;

namespace Cd_Rom_Prog
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        [DllImport("winmm.dll", EntryPoint = "mciSendStringA",
        CharSet = CharSet.Ansi)]
        protected static extern int mciSendString(string lpstrCommand,
        StringBuilder
        lpstrReturnString,
        int uReturnLength,
        IntPtr hwndCallback);

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            int ret = mciSendString("set cdaudio door open", null, 0, IntPtr.Zero);
        }

        private void button2_Click(object sender, EventArgs e)
        {
            int ret = mciSendString("set cdaudio door closed", null, 0, IntPtr.Zero);
        }
    }
}