SlickGrid single/multiple Row Selection

HTML

<script src="http://code.jquery.com/jquery-1.10.2.min.js"></script>
<script src="http://code.jquery.com/ui/1.10.3/jquery-ui.js"></script>
<script src="http://mleibman.github.io/SlickGrid/lib/jquery.event.drag-2.2.js"></script>
<script src="http://mleibman.github.io/SlickGrid/slick.core.js"></script>
<script src="http://mleibman.github.io/SlickGrid/plugins/slick.checkboxselectcolumn.js"></script>
<script src="http://mleibman.github.io/SlickGrid/plugins/slick.autotooltips.js"></script>
<script src="http://mleibman.github.io/SlickGrid/plugins/slick.cellrangedecorator.js"></script>
<script src="http://mleibman.github.io/SlickGrid/plugins/slick.cellrangeselector.js"></script>
<script src="http://mleibman.github.io/SlickGrid/plugins/slick.cellcopymanager.js"></script>
<script src="http://mleibman.github.io/SlickGrid/plugins/slick.cellselectionmodel.js"></script>
<script src="http://mleibman.github.io/SlickGrid/plugins/slick.rowselectionmodel.js"></script>
<script src="http://mleibman.github.io/SlickGrid/controls/slick.columnpicker.js"></script>
<script src="http://mleibman.github.io/SlickGrid/slick.formatters.js"></script>
<script src="http://mleibman.github.io/SlickGrid/slick.editors.js"></script>
<script src="http://mleibman.github.io/SlickGrid/slick.grid.js"></script>
<link rel="stylesheet" href="http://mleibman.github.io/SlickGrid/slick.grid.css">
<link rel="stylesheet" href="http://mleibman.github.io/SlickGrid/css/smoothness/jquery-ui-1.8.16.custom.css">
<link rel="stylesheet" href="http://mleibman.github.io/SlickGrid/controls/slick.columnpicker.css">
<link rel="stylesheet" href="https://rawgit.com/mleibman/SlickGrid/master/examples/examples.css">
<div style="position:relative">
    <div style="width:600px;">
        <div id="myGrid" style="width:180px;height:200px;"></div>
    </div>
</div>
<br>
<button id="single">Select Single rows</button>
 <button id="multiple">Select multiple rows</button>
    <button id="getRows">get selected rows</button><br><br>
    <div...

CSS

.slick-cell-checkboxsel {
    background: #f0f0f0;
    border-right-color: silver;
    border-right-style: solid;
}

JavaScript

var grid;
var data = [];
var options = {
    editable: false,
    enableCellNavigation: true,
    autoEdit: false,
};
var columns = [];
var selectedRows = [];

$(function () {
    for (var i = 0; i < 20; i++) {
        var d = (data[i] = {});
        d[0] = "Row " + i;
    }

    for (var i = 0; i < 3; i++) {
        columns.push({
            id: i,
            name: String.fromCharCode("A".charCodeAt(0) + i),
            field: i,
            width: 50,
        });
    }

    grid = new Slick.Grid("#myGrid", data, columns, options);
    selectActiveRow =  false;
    grid.setSelectionModel(new Slick.RowSelectionModel({
            selectActiveRow: false
        }));
       grid.onClick.subscribe(function (e,args) {
           debugger;
         alert(grid.getSelectedRows());
           if(selectActiveRow){
               if($.inArray(args.row, selectedRows) === -1){
                   selectedRows = [];
                   selectedRows.push(args.row)
               }else{
                  selectedRows = []; 
               }
           }else{
        ($.inArray(args.row, selectedRows) === -1) ? selectedRows.push(args.row) : selectedRows.splice(selectedRows.indexOf(args.row), 1);
                }
        grid.setSelectedRows(selectedRows);
          
    });
    
    $( "#single" ).click(function() {
        selectActiveRow = true;
      grid.setSelectionModel(new Slick.RowSelectionModel({
            selectActiveRow: true
        }));
    });
    
    $( "#multiple" ).click(function() {
        selectActiveRow = false;
      grid.setSelectionModel(new Slick.RowSelectionModel({
            selectActiveRow: false
        }));
    });
    
    $( "#getRows" ).click(function() {
        var str = '\n';
        for(var i=0; i<grid.getSelectedRows().length; i++){
            str+=grid.getSelectedRows()[i]+"\n";
        }
        $('#result').html('selected record ids are : \n'+str);
    });

})