private void btn_formCliente_Click(object sender, EventArgs e)
        {
            frm_cliente FormCliente = new frm_cliente();

            FormCliente.ShowDialog();
        }
        private void clientesToolStripMenuItem_Click(object sender, EventArgs e)
        {
            frm_cliente FormCliente = new frm_cliente();

            FormCliente.ShowDialog();
        }