js变量污染引起的诡异bug

js方法是这样的：

 //保存提货券JSON数据到隐藏字段
        saveVoucherListInfoToHiddenFiled: function () {
            //保存绑定商品信息
            var voucherLines = $("#tbVouchersBindCommodityList .cClz");
            var voucherModels = [];
            for (var i = 0; i < voucherLines.length; i++) {
                var $voucher = $(voucherLines[i]);
                var model = $voucher.data("voucher");
                model.BindCommodities = $voucher.data("bindcommodities");
                ////设置提货券的类型
                //model.BindType = model.BindCommodities.length ? model.BindCommodities[0].BindType : "COMMODITY";

                voucherModels.push(model);
            }
            $("#" + addVoucherModule.data.voucherListID).val(JSON.stringify(voucherModels));

            //绑定促销信息
            var voucherPromotionLines = $("#tbVouchersBindCommodityList .pClz");
            var voucherPromotionModels = [];
            for (var i = 0; i < voucherPromotionLines.length; i++) {
                var $voucherPromotion = $(voucherPromotionLines[i]);
                var modelPromotion = $voucherPromotion.data("voucher");
                modelPromotion.BindCommodities = $voucherPromotion.data("bindcommodities");
                voucherPromotionModels.push(modelPromotion);
            }
            $("#" + addVoucherModule.data.voucherPromotionListID).val(JSON.stringify(voucherPromotionModels));
        },

　　结果在

 var modelPromotion = $voucherPromotion.data("voucher");取到的值总是有一条与上一条一样的记录，最后将第二个i改成j才完事儿。。。。回头好好总结下