private void bar_DSDLBuuDien_LinkClicked(object sender, DevExpress.XtraNavBar.NavBarLinkEventArgs e)
 {
     if (formDLBD == null || formDLBD.IsDisposed)
     {
         formDLBD           = new QL_DaiLyBuuDien();
         formDLBD.MdiParent = this;
         formDLBD.Show();
     }
     else
     {
         formDLBD.Activate();
     }
 }
 private void button_dlbd_Click(object sender, EventArgs e)
 {
     if (formDLBD == null || formDLBD.IsDisposed)
     {
         formDLBD           = new QL_DaiLyBuuDien();
         formDLBD.MdiParent = this;
         formDLBD.Show();
     }
     else
     {
         formDLBD.Activate();
     }
 }