How to highlight bar in jqplot

To highlight bar in jqplot use function below

    function barHighlight(plot, sidx, pidx, points)
    {
        var s = plot.series[sidx];
        var canvas = plot.plugins.barRenderer.highlightCanvas;
        canvas._ctx.clearRect(0,0,canvas._ctx.canvas.width, canvas._ctx.canvas.height);
        s._highlightedPoint = pidx;
        plot.plugins.barRenderer.highlightedSeriesIndex = sidx;
        var opts = {fillStyle: s.highlightColors[pidx]};
        s.renderer.shapeRenderer.draw(canvas._ctx, points, opts);
        canvas = null;
    }

    function barUnhighlight(plot)
    {
        var canvas = plot.plugins.barRenderer.highlightCanvas;
        canvas._ctx.clearRect(0,0, canvas._ctx.canvas.width, canvas._ctx.canvas.height);
        for (var i=0; i<plot.series.length; i++) {
            plot.series[i]._highlightedPoint = null;
        }
        plot.plugins.barRenderer.highlightedSeriesIndex = null;
        plot.target.trigger('jqplotDataUnhighlight');
        canvas =  null;
    }