var data = [
    {x: 100, y: 100},	{x: 150, y: 150},	{x: 200, y: 100},
    {x: 250, y: 150},	{x: 300, y: 100},	{x: 350, y: 150}
];

var data = [
    {x: 100, y1: 100, y0: 150},	{x: 150, y1: 150, y0: 200},	{x: 200, y1: 100, y0: 150},
    {x: 250, y1: 150, y0: 200},	{x: 300, y1: 100, y0: 150},	{x: 350, y1: 150, y0: 200}
];

var area = d3.area()
        .x(function (d) {return d.x;})
        .y0(function (d) {return d.y0;})
        .y1(function(d){return d.y1;});