Fiabilité chronomètre

using System;
using System.Windows.Forms;

namespace Chronometre
{
    public partial class Form_Chrono : Form
    {

        public Form_Chrono()
        {
            InitializeComponent();
        }
        int h= 0;
        int m = 0;
        int s = 0;
        int ms = 0;
        private void timer_Tick(object sender, System.EventArgs e)
        {
            ms++;
            lab_Mili.Text = ms.ToString();
            if (ms >= 10)
            {
                ms = 0;
                s++;
                lab_S.Text = s.ToString();
                lab_Mili.Text = ms.ToString();


            }
            if (s >= 10) 
            {
                s = 0;
                m++;
                lab_M.Text = m.ToString();
                lab_S.Text = s.ToString();
            }
            if (m >= 60)
            {
                m = 0;
                h++;
                lab_H.Text = h.ToString();
                lab_M.Text = m.ToString();
            }

        }
        
        private void bt_demarrer_Click(object sender, System.EventArgs e)
        {
            timer.Enabled = true;
            timer.Interval = 100;
            timer.Tick += new EventHandler(timer_Tick);
            timer.Start();
        }

  
        private void bt_stop_Click(object sender, System.EventArgs e)
        {
            timer.Stop();
         }

        private void bt_reprendre_Click(object sender, System.EventArgs e)
        {
            timer.Start();
        }

        private void Bt_Split_Click(object sender, System.EventArgs e)
        {

        }

        private void bt_raz_Click(object sender, System.EventArgs e)
        {
            timer.Stop();
            timer.Dispose();
            ms = 0;
            s = 0;
            m = 0;
            h = 0;
        }
    }
}