protected void cbl_SelectedIndexChanged(object sender, EventArgs e) { this.Hidden1.Value = ""; string[] c = { "1", "2", "3", "4", "5", "6", "7", "8", "9" }; for (int i = 0; i < cbl.Items.Count; i++) { c[i] = cbl.Items[i].Selected ? (i + 1).ToString() : "0"; } // exec stored procedure [dbo].[GetMapByCategoriesEN] string a = JsonConvert.SerializeObject(lq.getMapByCategoriesEN( c[0], c[1], c[2], c[3], c[4], c[5], c[6], c[7], c[8] ), Formatting.Indented); this.Hidden1.Value = "{\"Resource\":" + a + "}"; }