Jquery的ajax第二回不发送请求，请帮忙看一下原因

Jquery的ajax第二次不发送请求，请帮忙看一下原因。
 function lbtnStop_Click(operateType) {
            var rows = grid.getSelecteds();
            var l = rows.length;
            if (l == 0) {
                AlertErrorMessage("x0001");
            }
            else {
                var s = "";
                for (var i = 0; i < l; i++) {
                    var row = rows[i];
                    s += row.ID;
                    if (i != l - 1)
                        s += "|";
                };

                $.ajax({
                    url: "/Controls/MiniUI/Data/AjaxFinishDataService.ashx",
                    Type: "post",
                    data: {
                        ids: s,
                        operateType: operateType,
                        bllclassName: "Sale.Sale_QuotationSheetDetail",
                        finishInMaster: false
                    },
                    success: function (text) {
                        if (text == "True") {
                            alert("操作成功！");
                            grid.reload();
                        }
                        else
                            alert(text);
                    },
                    error: function (jqXHR, textStatus, errorThrown) {
                        alert(jqXHR.responseText);
                    }
                });
            }
        }

在首次执行的时候，/Controls/MiniUI/Data/AjaxFinishDataService.ashx页面可以接收到请求，但 lbtnStop_Click方法第二次执行的时候， AjaxFinishDataService.ashx页面就没有接收到请求了，请问大家这个是怎么回事呢？
------解决方案--------------------
cache:false

$.ajax({

   type: "POST",

   url: "some.php",


   cache:false,

    success: function(msg){

      alert( "Data Saved: " + msg );

   }

 });

------解决方案--------------------
在 /Controls/MiniUI/Data/AjaxFinishDataService.ashx  加一个随机数