private void btn_Home_Click(object sender, EventArgs e)
        {
            CheckForChildWindow();
            HomeWindow child = new HomeWindow();

            child.MdiParent = this;
            child.Show();
            lbl_Title.Text = "Home";
        }
        private void OpenHomeWindow()
        {
            CheckForChildWindow();
            HomeWindow child = new HomeWindow();

            child.MdiParent = this;
            child.Show();
            lbl_Title.Text = "Home";
        }