更新事件不工作

更新事件不工作，当我点击更新按钮，自动重定向到登录页面的URL（返回URL）.........

string ItemNo = Convert.ToString(Session["EditValue"]);

            this.WriteToItemDataset(ItemNo);            

            this.errorMessageHtmlCell.InnerText = "Record(s) saved successfully."; //+ ItemNo;

            this.errorMessageHtmlCell.Attributes.Add("style", "color:Green");

            BindDataLIst();

            Editor3.Value = "";

            trMsgContent.Visible = true;

            trEditorMsg.Visible = false;