D3.js zoomable horizontal stacked bar

Question

I'm trying apply brush to my stacked bar chart.

http://jsfiddle.net/seurolandolero/bzwhb7mw/

function brushed() {
    var e = brush.extent();
    var e0 = e[0];
    var e1 = e[1];

    if (e0==e1) { 
        //alert("No brush selected");     
    } else {   
        xScale.domain(brush.empty() ? xScale.domain() : brush.extent());               
    }

    focus.select(".x.axis").call(xAxis);
}

I'm based on http://fiddle.jshell.net/seurolandolero/1of1kp53/.

What's wrong in my code? Thanks.