svg Scroll bar using D3 brush

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.2.2/d3.min.js"></script>
<svg width="960" height="1000"></svg>

CSS

.area {

    fill: steelblue;

    clip-path: url(#clip);

  }

JavaScript

var svg = d3.select("svg"),

    margin = { top: 20, right: 20, bottom: 110, left: 40 },

    margin2 = { top: 430, right: 20, bottom: 30, left: 40 },

    width = +svg.attr("width") - margin.left - margin.right,

    height = +svg.attr("height") - margin.top - margin.bottom,

    height2 = +svg.attr("height") - margin2.top - margin2.bottom;



  svg.append("defs").append("clipPath").attr("id", "clip").append("rect").attr("width", width).attr("height", 150);



  var x = d3.scaleTime().range([0, width]),
    x2 = d3.scaleTime().range([0, width]),
    y = d3.scaleLinear().range([0, 10]),
    y2 = d3.scaleLinear().range([height2, 0]);

  var data = [];

  for (var i = 0; i < 10; i++) {

    data.push(i);

  }



  var svg = d3.select('svg');
  var scale = d3.scaleLinear().domain([20, 30]).range([10, 450])


  function brushmoved() {

    // var s = d3.event.selection;

    var s = d3.event.selection || y2.range();

    d3.select('.asst').attr("transform", function (d, i) { return "translate(" + 0 + "," + (-s[1]) + ")"; });

    if (s == null) {

      //...

    } else {

      //var sx = s.map(x.invert);

      //circle.classed("active", function(d) { return sx[0] <= d && d <= sx[1]; });

      // handle.attr("display", null).attr("transform", function(d, i) { return "translate(" + s[i] + "," + height / 2 + ")"; });

      //...

    }

  }



  count = 0;







  var focus = svg.append("g").attr("class", "focus area").attr("transform", "translate(" + margin.left + "," + margin.top + ")").append("g").attr('class', 'asst').selectAll("text").data(data).enter();

  focus.append('text').text(function (d) { return d }).attr('y', function (d, i) {

    count += 20;

    return count;

  });





  //POSTION XY //WIDTH,HEIGHT

  var brush = d3.brushY().extent([[0, 0], [10, 150]]).on("start brush end", brushmoved);

  

  var g = svg.append('g')

  var gBrush = g.append("g").attr("class", "brush").call(brush);

  d3.selectAll('.brush>.handle').remove();



 ...