// click vào button thêm món
private void barButtonItem9_ItemClick(object sender, ItemClickEventArgs e)
{
DanhSachBan DSB = new DanhSachBan();
addpage(fr_main, "Thêm món", DSB);
}
private void navBarItem13_LinkClicked(object sender, DevExpress.XtraNavBar.NavBarLinkEventArgs e)
{
DanhSachBan DSB = new DanhSachBan();
addpage(fr_main, "Thêm món", DSB);
}