C#

private void listView1_SelectedIndexChanged(object sender, EventArgs e)
{ListView lv = (ListView)sender;

ListViewItem item = new listviewitem();
if (item != null)
{
switch (item.Text)
{
case "Stock":
ShowStockForm();
break;
case "Information":
ShowInfoForm();
break;
case "Quit":
QuitApplication();
break;
}
}
}

private void QuitApplication()
{
Application.Exit();
}


private void ShowInfoForm()
{
InfoForm form = new InfoForm();
form.ShowDialog();
}

private void ShowStockForm()
{
StockForm form = new StockForm();
form.ShowDialog();
}
}

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;
string s2 = textBox2.Text;
SqlCeConnection cnx = new SqlCeConnection();
string wCS = String.Format("DATA SOURCE = '{0}';", Program.gFichierBase);
cnx.ConnectionString = wCS;
string req = "SELECT * FROM Connexion WHERE Login = @login AND MotPasse = @pass";
SqlCeCommand cmd = new SqlCeCommand(req, cnx);
SqlCeParameter login = new SqlCeParameter("login", s1);
cmd.Parameters.Add(login);
SqlCeParameter pass = new SqlCeParameter("pass", s2);
cmd.Parameters.Add(pass);
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");
}
}
The problem is that any login and password I enter,it lets me pass"successful authentification"
How can i modify this code?
Thanks