C#

<code>
    Excel.Application app = new Microsoft.Office.Interop.Excel.ApplicationClass(); 
    try 
    { 
        app.Visible = false; 
        Excel.Workbook wBook = app.Workbooks.Add(true); 
        Excel.Worksheet wSheet = wBook.Worksheets[1] as Excel.Worksheet; 
        if (dt.Rows.Count > 0) 
        { 
            int row = 0; 
            row = dt.Rows.Count; 
            int col = dt.Columns.Count; 
            for (int i = 0; i < row; i++) 
            { 
                for (int j = 0; j < col; j++) 
                { 
                    string str = dt.Rows[i][j].ToString(); 
                    wSheet.Cells[i + 2, j + 1] = str; 
                } 
            } 
        } 
        int size = dt.Columns.Count; 
        for (int i = 0; i < size; i++) 
        { 
            wSheet.Cells[1, 1 + i] = dt.Columns[i].ColumnName; 
        } 
        app.DisplayAlerts = false; 
        app.AlertBeforeOverwriting = false; 
        wBook.Save(); 
        app.Save(filePath); 
        app.SaveWorkspace(filePath); 
        app.Quit(); 
        app = null; 
    } 
    catch (Exception err) 
    {
        return -1;
    } 
    finally 
    { 
    }
   </code>

CheckBox chkSelection;
foreach (DataGridItem item in contacts.Items)
{
    chkSelection = (CheckBox)item.FindControl("chkSelection");
    if (chkSelection.Checked == true)
    {
        Control contact = (Control)item.FindControl("phone_num");//I don't know what to do here....
        errors0.Text += contact.ToString();
        errors0.Visible = true;
        //string contact = contacts.SelectedItem.Cells[4].Text;
     }
}

private void button1_Click(object sender, EventArgs e)
{
/*string req = "select Login, MotPasse from Connexion";
DataTable tab = new DataTable();
SqlCeCommand com = new SqlCeCommand(req, sqlceconn);
SqlCeDataAdapter ada = new SqlCeDataAdapter(com);
ada.Fill(tab);*/
string s1 = textBox1.Text.ToString();
string s2 = textBox2.Text.ToString();
BaseGmaoLocaleDataSet2 dat = new BaseGmaoLocaleDataSet2();
DataRow[] foundRows;
foundRows = dat.Tables["Connexion"].Select("Login like s1 and MotPasse like s2");

if (foundRows != null)
{
MessageBox.Show("Authentification réussie");
MenuP m = new MenuP();
m.Show();
}
else
{
MessageBox.Show("Login ou mot de passe incorrect veuillez réessayer");
}
}}}