private void DataBillFrmToolStripMenuItem_Click(object sender, EventArgs e)
 {
     if (FrmDataBill.IsDisposed)
     {
         FrmDataBill = new DataBillFrm();
         FrmDataBill.MdiParent = this;
         FrmDataBill.Show();
     }
     else
     {
         if (FrmDataBill.Visible)
         {
             FrmDataBill.WindowState = FormWindowState.Normal;
             FrmDataBill.Focus();
         }
         else
         {
             FrmDataBill.MdiParent = this;
             FrmDataBill.Show();
         }
     }
     FrmDataBill.Icon = MCls.MakeIcon(global::StoreAccount.Properties.Resources.dataBillFrm, 16, false);
 }