Inserting data

Question

I want to insert data into an existing database

for example:

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

public class frmMain : System.Windows.Forms.Form

{

[STAThread]

static void Main()

{

Application.Run(new frmMain());

}

protected const string SQL_CONNECTION_STRING = "Server=localhost;" + "DataBase=Northwind;" + "Integrated Security=SSPI;Connect Timeout=5";

private string Connectionstring = SQL_CONNECTION_STRING;

private bool HasConnected = false;

private string Mode = "Update";

private void btnAdd_Click(object sender, System.EventArgs e)

{

ClearForm();

Mode = "Add";

btnDelete.Enabled = false;

dont know how to end the it,the issue im having is connecting to sql 2005 server database.

thanks for your anticipated corpration