Kendo Grid and Chart

HTML

<link rel="stylesheet" href="http://cdn.kendostatic.com/2012.2.621/styles/kendo.common.min.css">
<script src="http://cdn.kendostatic.com/2012.2.621/js/kendo.all.min.js"></script>
<link rel="stylesheet" href="http://cdn.kendostatic.com/2012.2.621/styles/kendo.mobile.all.min.css">
<link rel="stylesheet" href="http://cdn.kendostatic.com/2012.2.621/styles/kendo.default.min.css">
<div id="grid"></div>
<div>Avg Value:<span id="val">an</span></div>

JavaScript

var sharedDataSource = new kendo.data.DataSource({
    data: [
        { id: 1, itemValue: 10, item: "Item1" },
        { id: 2, itemValue: 12, item: "Item2" },
        { id: 3, itemValue: 15, item: "Item3" },
        { id: 4, itemValue: 10, item: "Item4" },
        { id: 5, itemValue: 10, item: "Item5" },
        { id: 6, itemValue: 11, item: "Item6" }       
    ],
    schema: {
        model: {
            id: "id",
            fields: {
                id: { type: "number", editable: false },
                itemValue: { type: "number" },
                item: { type: "string" }                
            }
        }            
    }
});
    
    
$("#grid").kendoGrid({
    dataSource: sharedDataSource,
    change: calcAvg,
    dataBound: calcAvg,
    autoBind: false,
    editable: true,
    toolbar: ["save", "cancel"]
});

function calcAvg()
{
    var grid = GetGrid('grid')
    if (grid == null) return;

    var ds = grid.dataSource;
    if (ds == null) return;

    var data = ds.data();
    if (data == null) return;

    var target = $('#val');
    var vSum = 0.0;
    if (data && target) {
        for (var i = 0; i < data.length; i++) {
            vSum += data[i].itemValue;
        }
        var avg = vSum/data.length;
        if(avg < 10 || avg > 15)
            target.html("out of range");
        else
            target.html(avg.toString());            
        //var out = avg < 10 || avg < 15 ? "out of range" : avg.ToString();
        //target.html(out);

    }
}

function GetGrid(gridId) {
    return $('#' + gridId).data("kendoGrid");
}
calcAvg();
sharedDataSource.read();
$('.k-grid-save-changes').on('click', '', onChange);