在javascript中用逗号分隔的字符串分割值

这是我的问题：

我有RadListBox，我正在尝试获取值并将其附加，以便结果显示为："1,2,3,4"，但我正在返回：1,2,3,4，有人知道我该如何做到这一点吗？

问题从这里开始：

var sbLocationsIDS = new StringBuilder();
             for (i = 0; i < LocationIDS.get_items().get_count(); i++) {
                 sbLocationsIDS.append(LocationIDS.getItem(i).get_value()+ ",");  
             }

结果：sbLocationsIDS=1,2,3,4，而不是'1,2,3,4'

代码的其余部分：

 function openNewTab(url) {
         var captureURL = url;
         var win = window.open(captureURL, '_blank');
         win.focus();
     }
     function GetComparisonsReport(sender, args) {
         var isValid = Page_ClientValidate('validateComparisons');
         if (isValid) { // If its true is going to fire the rest of the code
             var SessionID = getUrlVars()["SessionID"];
             var companyCodeVal = document.getElementById("<%=hfC.ClientID%>").value;
             var LocationIDS = $find("<%=rlbSelectedLocation.ClientID %>");
             var CategoriesIDS = $find("<%=rlbSelectedCategory.ClientID %>");
             var fileType = $find("<%=rcbFileType.ClientID %>");
             var fromFirstPeriod = $find("<%=rdpFromFirstPeriod.ClientID %>");
             var toFirstPeriod = $find("<%=rdpToFirstPeriod.ClientID %>");
             var fromSecondPeriod = $find("<%=rdpFromSecondPeriod.ClientID %>");
             var toSecondPeriod = $find("<%=rdpToSecondPeriod.ClientID %>");;
              if (LocationIDS.get_items().get_count() < 0) {
                 radalert("Please choose locations and select the Add button.<h3 style='color: #ff0000;'></h3>", 420, 170, "Case Global Alert");
                 return;
             }
             if (CategoriesIDS.get_items().get_count() < 0) {
                 radalert("Please choose categories and select the Add button.<h3 style='color: #ff0000;'></h3>", 420, 170, "Case Global Alert");
                 return;
             }
             var fromFirstPeriodDateValSelected = fromFirstPeriod.get_dateInput().get_selectedDate().format("yyyy/MM/dd");
             var toFirstPeriodDateValSelected = toFirstPeriod.get_dateInput().get_selectedDate().format("yyyy/MM/dd");
             var fromSecondPeriodDateValSelected = fromSecondPeriod.get_dateInput().get_selectedDate().format("yyyy/MM/dd");
             var toSecondPeriodDateValSelected = toSecondPeriod.get_dateInput().get_selectedDate().format("yyyy/MM/dd");
             var fileTypeValSelected = fileType.get_selectedItem().get_value();

             var sbLocationsIDS = new StringBuilder();
             for (i = 0; i < LocationIDS.get_items().get_count(); i++) {
                 sbLocationsIDS.append(LocationIDS.getItem(i).get_value()+ ",");  // The problem is here!!!
             }
             var sbCategoriesIDS = new StringBuilder();
             for (i = 0; i < CategoriesIDS.get_items().get_count(); i++) {
                 sbCategoriesIDS.append(CategoriesIDS.getItem(i).get_value() + ",");
             }
             var ComparisonsURL = (String.format("https://www.test.com/cgis/{0}/reports/ConnectTorptIncidentsCountByLocationInterval.asp?SessionID={1}&locString={2}&catString={3}&FromDate1={4}&&ToDate1={5}&FromDate2={6}&ToDate2={7}&ExportType={8}", companyCodeVal, SessionID, sbLocationsIDS, sbCategoriesIDS, fromFirstPeriodDateValSelected, toFirstPeriodDateValSelected, fromSecondPeriodDateValSelected, toSecondPeriodDateValSelected, fileTypeValSelected));
             openNewTab(ComparisonsURL);
         }
     }
     String.format = function () {
         // The string containing the format items (e.g. "{0}")
         // will and always has to be the first argument.
         var theString = arguments[0];
         // start with the second argument (i = 1)
         for (var i = 1; i < arguments.length; i++) {
             // "gm" = RegEx options for Global search (more than one instance)
             // and for Multiline search
             var regEx = new RegExp("''{" + (i - 1) + "''}", "gm");
             theString = theString.replace(regEx, arguments[i]);
         }
         return theString;
     }
     function getUrlVars() {
         var vars = {};
         var parts = window.location.href.replace(/[?&]+([^=&]+)=([^&]*)/gi, function (m, key, value) {
             vars[key] = value;
         });
         return vars;
     }
     // Initializes a new instance of the StringBuilder class
     // and appends the given value if supplied
     function StringBuilder(value) {
         this.strings = new Array("");
         this.append(value);
     }
     // Appends the given value to the end of this instance.
     StringBuilder.prototype.append = function (value) {
         if (value) {
             this.strings.push(value);
         }
     }
     // Clears the string buffer
     StringBuilder.prototype.clear = function () {
         this.strings.length = 1;
     }
     // Converts this instance to a String.
     StringBuilder.prototype.toString = function () {
         return this.strings.join("");
     }