using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Windows.Forms;
using System.Runtime.InteropServices;
 
namespace Sample
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
 
        [DllImport("kernel32.dll")]
        public static extern bool Beep(int BeepFreq, int BeepDuration);
 
        private void button1_Click(object sender, EventArgs e)
        {
            Beep(500, 100);
        }
    }
}