private void btnDangNhap_ItemClick(object sender, ItemClickEventArgs e) { frmDangNhap frm = new frmDangNhap(); frm.Owner = this; frm.ShowDialog(); ribbon.SelectedPage= Menu_Action; if (Class.App.client_User != "admin") { Menu_Get.Visible = false; groupDHCP.Visible = false; if (Class.App.client_User == "super") { btnDanhSachNode.Enabled = true; btnDanhsachDevice.Enabled = true; } else { btnDanhSachNode.Enabled = false; btnDanhsachDevice.Enabled = false; } if (Class.App.client_User == "lapmoi") { groupDHCP.Visible = true; } } else { Menu_Get.Visible = true; groupDHCP.Visible = true; } }