title: jqGrid export to excel issue when loadonce option is setted to false
body: <p>I have an ASP.net MVC solution and use jqGrid in it. To have a better performance I use <code>loadonce: false</code> as an option and it should be in this way, unfortunately It seems to be not supported by jqGrid because I cannot find any sign of that throughout my search.</p>
  
  <pre><code>$(document).ready(function () {
      $("#jqGrid").jqGrid(
          {
              url: "/Student/GetStudents",
              mtype: "GET",
              datatype: "json",
              contentType: "application/json; charset-utf-8",
  
              jsonReader: {
                  root: "rows",
                  id: "StudentId",
                  repeatitems: false
              },
              colNames: ['StudentId', 'FirstName', 'LastName'],
              colModel: [
                  { label: 'StudentId', name: 'Id', key: true, width: 75 },
                  { label: 'FirstName', name: 'FirstName', width: 150 },
                  { label: 'LastName', name: 'LastName', width: 150 },
  
              ],
              viewrecords: true,
              loadonce: false,
              width: '100%',
              height: 'auto',
              rowNum: 20,
              rowList: [20, 30, 50],
              sortable: true,
              sortname: 'Id',
              pager: "#jqGridPager",
  
              autoencode: true,
              scroll: false,
              pgbuttons: true,
              autowidth: true,
              shrinkToFit: false,
              forceFit: false,
              gridview: false,
              height: '100%',
              scrollrows: true,
              page: 1,
              //pagerpos: 'center',
              toppager: true,
              recordpos: 'right',
              multiselect: true,
              multiboxonly: true,
              direction: 'rtl',
              ignoreCase: true,
              caption: "",
              rownumbers: true
          });
      $('#jqGrid').jqGrid('navGrid', '#jqGridPager', {
          search: true,
          searchtext: "Search",
          edit: false,
          add: false,
          del: false,
          excel: true,
          refresh: false,
  
      }, {}, {}, {}, {
          closeOnEscape: true,
          closeAfterSearch: true,
          ignoreCase: true,
          multipleSearch: false,
          multipleGroup: false,
          showQuery: false,
          sopt: ['cn', 'eq', 'ne'],
          defaultSearch: 'cn'
      })
      $('#jqGrid').jqGrid('navButtonAdd', '#jqGridPager', {
          caption: "Export to Excel",
          //buttonicon: "ui-icon-disk",
          buttonicon: "ui-icon-folder-open",
          onClickButton: function () {
              exportToExcel();
          },
  
      });
  });
  function exportToExcel(data, e) {
      exportExcelFile(data);
  }
  
  
  function exportExcelFile() {
      debugger;
  
      var data = $('#jqGrid')[0].addLocalData(true);
      var ua = window.navigator.userAgent;
      var msie = ua.indexOf("MSIE");
      if (msie &gt; 0 || !!navigator.userAgent.match(/Trident.*rv\:11\./)) {
          frame1.document.open("txt/html", "replace");
          frame1.document.write(setTableOfData(data));
          frame1.document.close();
          frame1.focus();
          sa = frame1.document.execCommand("SaveAs", true, "text.xls");
      } else
          $('#jqGrid').jqGrid('exportToExcel', { fileName: "exportedExcel.xls", navigator: true });
  }
  
  function setTableOfData(data) {
      var htmlString = '&lt;table&gt;';
      var header = '&lt;tr&gt;&lt;td&gt;StudentId&lt;/td&gt;&lt;td&gt;FirstName&lt;/td&gt;&lt;td&gt;LastName&lt;/td&gt;&lt;/tr&gt;';
      htmlString += header;
      for (var i = 0; i &lt; data.length; i++) {
          var tag = '&lt;tr&gt;&lt;td&gt;' + data[i].Id + '&lt;/td&gt;&lt;td&gt;' + data[i].FirstName + '&lt;/td&gt;&lt;td&gt;' + data[i].LastName + '&lt;/td&gt;&lt;/tr&gt;';
          htmlString += tag;
      }
      htmlString += '&lt;/table&gt;';
      return htmlString;
  }
  </code></pre>