private void btnCauHinh_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
{
Form frm = IsActive(typeof(FrmConfig));
if (frm == null)
{
var forms = new FrmConfig(connectString);
forms.MdiParent = this;
forms.Show();
}
else
{
frm.Activate();
}
}
