jqgrid edit button accessing a set of checkboxes that are selected

I have the below code in my jqgrid

<script type="text/javascript">
    jQuery(document).ready(function() {

        var grid = jQuery("#list");
        $("#editBtn").click(function() {
           alert("hi");                            });


        jQuery("#list").jqGrid({
            url: '<%= Url.Action("DynamicGridData") %>',
            datatype: 'json',
            mtype: 'POST',

            colNames: ['checkbox',  'Id','col1','col2' ],
            colModel: [
      { name: 'checkbox', index: 'checkbox', sortable: false, formatter: "checkbox", formatoptions: { disabled: false }, editable: true, edittype: "checkbox" },
               { name: 'Id', index: 'Id', search: false, stype: 'text', sortable: true, sorttype: 'int', hidden: true },
      { name: 'col1', index: 'col1', search: false, stype: 'text', sortable: true, sorttype: 'int', search: false, hidden: true },
      { name: 'col2', index: 'col2', sortable: true, search: false, width: 30, stype: 'int' } ],
            pager: jQuery('#pager'),
            rowNum: 40,
            rowList: [20, 40, 60, 100],
            sortname: 'Id',
            sortorder: 'asc',
            gridview: true,
            autowidth: true,
            rownumbers: true,
        开发者_JS百科    viewrecords: true,
            toppager: true,
            height: "100%",
            width: "100%",
           caption: 'Grid Data'
        });



    });

I can fire the test alert in the editBtn function, how can a user access the id column of the records that have their checkboxes selected by the user?

---

use the following code to get the Id column data of which checkboxes are ticked...

var grid = jQuery("#list");
$("#editBtn").click(function() {
   var str = '';
   var data = grid.getRowData();
   for(i=0;i<data.length;i++){
        if(data[i].checkbox==='Yes')
            str += data[i].Id+',';
   }
   alert(str);
});

str variable consists of the values of Id column for which checkbox is selected by user.