C#

"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\dbs\database.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True"

User Id=myUserName;Password=myPassword

#region Configure MenuItem

private bool MyFormStarted = false;
private MyForm MyDlg;

private void MyDlgMenuItem_Click(object sender, EventArgs e)
{
    if (MyFormStarted)
    {
        if (MyDlg.InvokeRequired)
        {
            MyDlg.BeginInvoke((ThreadStart)delegate()
            {
                //MyDlg.Show();
                //MyDlg.BringToFront();
                //MyDlg.Focus();
            });
        }
        else
        {
            //MyDlg.Show();
            //MyDlg.BringToFront(); 
            //MyDlg.Focus();
        }
    }
    else
    {
        MyFormStarted = true;

        new Thread(new ThreadStart(delegate
        {
            MyDlg = new MyForm ();
            MyDlg.ShowDialog();
            MyDlg.Dispose();

            MyFormStarted = false;
        })).Start();
    }
}

#endregion

MyDlg.BringToFront(); 
MyDlg.Focus();