C# ve SQL

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace kronometre
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
public int KalanSure;

private void button1_Click(object sender, EventArgs e)
{
KalanSure = System.Convert.ToInt32(txtSure.Text);
lbSure.Text = System.Convert.ToString(KalanSure);
lbKayit.Items.Add("Kronometre başladı:" + DateTime.Now.TimeOfDay.ToString());
timer1.Interval = System.Convert.ToInt32(comboBox1.Text);
timer1.Start();
}

private void button2_Click(object sender, EventArgs e)
{
timer1.Stop();
lbKayit.Items.Add("Kronometre Durduruldu:" + DateTime.Now.TimeOfDay.ToString());
}

private void timer1_Tick(object sender, EventArgs e)
{
KalanSure = KalanSure - 1;
lbSure.Text = System.Convert.ToString(KalanSure);

if (KalanSure == 0)
{
timer1.Stop();
lbKayit.Items.Add("Süre Doldu" + DateTime.Now.TimeOfDay.ToString());
MessageBox.Show("Süren Doldu Görmüyormusun");

}
}

private void Form1_Load(object sender, EventArgs e)
{

}
}
}