i user grid_InitializeDataSource function to do something,

string departmentId = Request.Form["hid_DepartmentId"];
            string performanceCheckId = Request.Form["hid_PerformanceCheckId"];
            string employeeNumber = Request.Form["hid_EmployeeNumber"];

            string performanceIds = Request.Form["hid_PerformanceIds"];
            string button_click = Request.Form["hid_button_click"];

            // 先处理数据
            if (!string.IsNullOrEmpty(button_click))
            {
                string strReturn = SaveIndividualDepartmentPerformance(button_click, String2ArrayList(performanceIds));
                hid_save_message.Value = "12345";
            }

            DataSet dst = new DataSet();

            Performance performance = new Performance();

            performance.FillPerformanceByDepartmentId(dst, departmentId, performanceCheckId, employeeNumber);

            e.DataSource = dst;

i want to get "12345" by OnAfterResponseProcess function in client, how can i do? OnAfterResponseProcess function like the this:

        function wg_performance_OnAfterResponseProcess(controlId, actionName, lastRequestObject, xmlResponseObject) {
            if (document.all["hid_button_click"].value != '') {
                EnableControls();
                document.all["hid_button_click"].value = '';
                var statusLabel = document.getElementById("save_message");
                var v_hid_save_message = document.getElementById("hid_save_message");
                if (v_hid_save_message.value == '') {
                    statusLabel.innerHTML = '设定成功！';
                    statusLabel.className = 'clsSucceed';
                }
                else {
                    statusLabel.innerHTML = v_hid_save_message.value;
                    statusLabel.className = 'clsFailed';
                }
                v_hid_save_message.value = '';
            }
        }

thanks