private void compraToolStripMenuItem_Click(object sender, EventArgs e)
        {
            bool administrador = false;
            if (this.permisos == 1) {
                administrador = true;
            }

            CompraForm form = new CompraForm(administrador);
            form.MdiParent = this;
            form.Show();
        }
 private void buttonCompra_Click(object sender, EventArgs e)
 {
     CompraForm comp = new CompraForm();
     comp.ShowDialog();
 }