private void listadoCompletoToolStripMenuItem_Click(object sender, EventArgs e)
 {
     if (rptClien == null)
     {
         rptClien             = new frmRptClientes();
         rptClien.MdiParent   = this;
         rptClien.FormClosed += new FormClosedEventHandler(rptClien_FormClosed);
         rptClien.Show();
     }
     else
     {
         rptClien.Activate();
     }
 }
 void rptClien_FormClosed(object sender, FormClosedEventArgs e)
 {
     rptClien = null;
 }