I have problems with the zoom event. My zoom event doesnt call the function after zooming. The event should let me zoom the chart x-Axis and x-Scale. It doesnt even print out the 'zoom'. What am I doint wrong?

    chart = d3.select(self.renderTo)
        .append('svg')
        .attr('width', self.width)
        .attr('height', self.height)
        .attr('class', 'gantt-chart');

    chart.append('defs').append('clipPath')
        .attr('id', 'clip')
        .append('rect')
        .attr('width', marginWidth)
        .attr('height', marginHeight);

     xScale = d3.scaleTime()
        .domain(getTimeDomain())
        .range([0, marginWidth]);

    yScale = d3.scaleLinear()
        .domain([0, laneLength])
        .range([0, marginHeight]);

    xAxis = d3.axisBottom().scale(xScale)
        .ticks(5);

    yAxis = d3.axisLeft().scale(yScale)
        .ticks(laneLength)
        .tickFormat('');


    zoom = d3.zoom()
        .on('zoom', function (event, d) { zoomFunction(event); });

    chart.call(zoom);


    function zoomFunction (event) {
    console.log('zoom');
    // create new scale ojects based on event
    var newXscale = d3.event.transform.rescaleX(xScale);
    console.log(event.transform);

    // update axes
    d3.select('.g.main.axis.date').call(xAxis.scale(newXscale));
};