How to save data from datagrid to SQL Server in C#

Hi,
Please go through the below sample code. I have created a datatable and bind with datagrid, Now if I add a row in the grid, it will get added into the datatabel. When user clicks save button, read the data from the data table and insert into the database.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace WindowsFormsApplication2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        DataTable dt = new DataTable();
        private void button1_Click(object sender, EventArgs e)
        {

            MessageBox.Show(dt.Rows.Count.ToString());
            //loop to read the data from data table
            foreach (DataRow dr in dt.Rows)
            {
                MessageBox.Show(dr[0].ToString()); //First col value
                MessageBox.Show(dr[1].ToString()); //second col value
                MessageBox.Show(dr[2].ToString()); //third col value
            }
            
        }

        private void Form1_Load(object sender, EventArgs e)
        {
           
            dt.Columns.Add("Name");
            dt.Columns.Add("Number");
            dt.Columns.Add("Age");

            dataGridView1.DataSource = dt;
        }
    }
}

Best Regards
Muthuraja