When no data in Grid , the rows should be displayed in Alternate colors

I have a AW grid, I am getting Blank grid when no data , instead i want the grid to be displayed in alternate colors.

Just set row count to > 0

<style>

    .aw-alternate-even {
        background: #def;
    }

</style>
<script>

    var obj = new AW.UI.Grid;
    obj.setRowCount(20);
    document.write(obj);

</script>