c# webbrowser ses kapatma sound disable webbrowser

using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace WinformsWB
{
    public partial class Form1 : Form
    {
        [DllImport("winmm.dll")]
        public static extern int waveOutGetVolume(IntPtr h, out uint dwVolume);

        [DllImport("winmm.dll")]
        public static extern int waveOutSetVolume(IntPtr h, uint dwVolume);

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            // save the current volume
            uint _savedVolume;
            waveOutGetVolume(IntPtr.Zero, out _savedVolume);

            this.FormClosing += delegate 
            {
                // restore the volume upon exit
                waveOutSetVolume(IntPtr.Zero, _savedVolume);
            };

            // mute
            waveOutSetVolume(IntPtr.Zero, 0);
            this.webBrowser1.Navigate("http://youtube.com");
        }
    }
}