Morris.Donut({
element: 'graph',
data: [
{value: 70, label: 'foo'},
{value: 15, label: 'bar'},
{value: 10, label: 'baz'},
{value: 5, label: 'A really really long label'}
],
formatter: function (x) { return x + "%"}
}).on('click', function(i, row){
console.log(i, row);
});