private void login_btn_Click(object sender, EventArgs e)
 {
     Forms.LoginForm loginForm = new Forms.LoginForm();
     loginForm.VisibleChanged += delegate(object source, EventArgs args)
     {
         if (!loginForm.Visible)
         {
             this.Show();
         }
     };
     loginForm.Show();
 }
 private void m_btn_ReturningUser_Click(object sender, EventArgs e)
 {
     Forms.LoginForm login = new Forms.LoginForm();
     login.Show();
     // this.Hide();
 }