if (settings.zoomIn) {
            settings.zoomIn.bind('mousedown.panZoom', eventData, function(event) {
                event.preventDefault(); event.data.target.panZoom('mouseDown', 'zoomIn');
            }).bind('mouseleave.panZoom mouseup.panZoom', eventData, function(event) {
                event.preventDefault(); event.data.target.panZoom('mouseUp');