private void btnHelp_Click(object sender, EventArgs e)
        {
            panelMenu.Width  = 32;
            panelMenu.Height = 2;
            btnAbrir.Enabled = true;
            lectorPDF pdf = new lectorPDF();

            pdf.Show();
        }
        private void btnHelp_Click(object sender, EventArgs e)
        {
            panelMenu.Width = 32;
            panelMenu.Height = 2;
            btnAbrir.Enabled = true;
            lectorPDF pdf = new lectorPDF();
            pdf.Show();


        }