anychart.onDocumentReady(function () {
var chart = anychart.cartesian();
var series = chart.area([
{x: "January", value: 2},
{x: "February", value: 5},
series.hoverFill(function () {
return anychart.color.darken(this.sourceColor);
chart.title("Set series hover fill parameter as a function");
chart.container("container");