private void btnAdd_Click(object sender, EventArgs e)
 {
     ClsManejoSession.SessionHelper objSession = ClsManejoSession.Login(txt_nickname.Text, txt_pass.Text);
     if (!objSession.isValid)
     {
         MessageBox.Show("Error:" + objSession.msgError);
     }
     else
     {
         frmMainSistema.SessionActiva = objSession;
         this.Close();
     }
 }
 public frmMainSistema()
 {
     InitializeComponent();
     SessionActiva = new ClsManejoSession.SessionHelper();
 }