private void bar_TH_TH_DT_LinkClicked(object sender, DevExpress.XtraNavBar.NavBarLinkEventArgs e)
 {
     if (formQLTHTHDT == null || formQLTHTHDT.IsDisposed)
     {
         formQLTHTHDT           = new QuanLyBaoCaoTHTHDT();
         formQLTHTHDT.MdiParent = this;
         formQLTHTHDT.Show();
     }
     else
     {
         formQLTHTHDT.Activate();
     }
 }
 private void button_QL_BC_ththdautu_Click(object sender, EventArgs e)
 {
     if (formQLTHTHDT == null || formQLTHTHDT.IsDisposed)
     {
         formQLTHTHDT           = new QuanLyBaoCaoTHTHDT();
         formQLTHTHDT.MdiParent = this;
         formQLTHTHDT.Show();
     }
     else
     {
         formQLTHTHDT.Activate();
     }
 }