//protected void grdSanPham_InitializeLayout(object sender, Infragistics.WebUI.UltraWebGrid.LayoutEventArgs e)
    //{
    //    e.Layout.Grid.Columns.FromKey("Command").AllowRowFiltering = false;
    //    e.Layout.Grid.Columns.FromKey("TenSanPham").FilterOperatorDefaultValue = FilterComparisionOperator.Contains;
    //    e.Layout.Grid.Columns.FromKey("Dates").FilterOperatorDefaultValue = FilterComparisionOperator.Contains;
    //    e.Layout.Grid.Columns.FromKey("TenNhomSanPham").FilterOperatorDefaultValue = FilterComparisionOperator.Contains;
    //    //if (rbtTatCa.Checked == true)
    //    //{
    //    //    e.Layout.Pager.AllowPaging = false;
    //    //}
    //    //else
    //    //{
    //    //    e.Layout.Pager.AllowPaging = true;
    //    //}
    //}
    //protected void rbtPhanTrang_CheckedChanged(object sender, EventArgs e)
    //{
    //    LoadData();
    //}
    //protected void rbtTatCa_CheckedChanged(object sender, EventArgs e)
    //{
    //    LoadData();
    //}
    private void LoadGianHang()
    {
        CuaHang ch = new CuaHang();
        DataSet ds = ch.SelectAll();

        ddlGianHang.DataSource = ds.Tables[0];
        ddlGianHang.DataTextField = "TenCuaHang";
        ddlGianHang.DataValueField = "CuaHangID";
        ddlGianHang.DataBind();

        ddlGianHang.Items.Insert(0, "Tất cả gian hàng");
        ddlGianHang.SelectedIndex = 0;
    }