how to update a database using a datagridview

Question

namespace UpdateDataWindowsFormDataGridView { public partial class Form1 : Form { private SqlDataAdapter da; private DataTable dt;

    public Form1()
    {
        InitializeComponent();

        // Configure display characteristics of the data grid view
        dataGridView.Anchor = AnchorStyles.Left | AnchorStyles.Right |
            AnchorStyles.Top | AnchorStyles.Bottom;
        this.Width = 500;

        this.Load += new EventHandler(Form1_Load);
    }

    void Form1_Load(object sender, EventArgs e)
    {
        // Set the data source of the data grid view
        dataGridView.DataSource = LoadData();
    }

    private DataTable LoadData()
    {
        string sqlConnectString = @"my connetion";

        string sqlSelect = "SELECT Id, IntField, StringField FROM DataGridView";

        // Create a data adapter and command builder
        da = new SqlDataAdapter(sqlSelect, sqlConnectString);
        SqlCommandBuilder cb = new SqlCommandBuilder(da);
        // Load a DataTable with schema and data from table DataGridView
        dt = new DataTable();
        da.FillSchema(dt, SchemaType.Source);
        da.Fill(dt);

        return dt;
    }

    private void saveButton_Click(object sender, EventArgs e)
    {

        da.Update(dt);
        MessageBox.Show("Changes saved.", "DataGridView",
            MessageBoxButtons.OK, MessageBoxIcon.Information);
    }
}

}

This is not my code but I just did exactly like this but on a extra note I have added a button which selects the value in the gridview…nw I want a button for just updating the gridview… wen I use this code the database remains unchanged(nothing happens)…. For the second button I have added the SQL dataadaptor and datatable publically hw t is in the prog but with a different object instance(name)..

This code is workin if I create a dummy form with just one gridview and a button, but not wen 2 buttons (one for select and 1 for update ).. is there any other way to do this..