ebola dots on a map

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js"></script>
  <script src='https://api.mapbox.com/mapbox.js/v2.2.3/mapbox.js'></script>
  <link href='https://api.mapbox.com/mapbox.js/v2.2.3/mapbox.css' rel='stylesheet' />
  
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
    #map {
      position: absolute;
      width: 100%;
      height: 100%;
    }
  </style>
</head>

<body>
  <h3>Map of Ebola Effected Countries</h3>
	<p>Select a country to add it to the map</p>
  
  United States--> <input type="checkbox" value="United States" onclick="updatemap(this)">
  Sierra Leone--> <input type="checkbox" value="Sierra Leone" onclick="updatemap(this)"><br>
  Liberia--> <input type="checkbox" value="Liberia" onclick="updatemap(this)">
  Nigeria--> <input type="checkbox" value="Nigeria" onclick="updatemap(this)">
<br>
  Guinea--> <input type="checkbox" value="Guinea" onclick="updatemap(this)">
  Senegal--> <input type="checkbox" value="Senegal" onclick="updatemap(this)">
<br>
  Democratic Republic of the Congo--> <input type="checkbox" value="Democratic Republic of the Congo" onclick="updatemap(this)">
  Spain--> <input type="checkbox" value="Spain" onclick="updatemap(this)">
<br>
  
  <script>
    function updatemap(checkbox) {
      d3.selectAll("circle").each( function(d) {
        if (d.properties.country == checkbox.value) {
          if (checkbox.checked) {
            d3.select(this).attr("visibility", "visible");
          }
          else {
            d3.select(this).attr("visibility", "hidden");
          }
        }
      });
    }
    
  </script>
  
  
  <div id="map"></div>
  <script>
    L.mapbox.accessToken = 'pk.eyJ1IjoiZW5qYWxvdCIsImEiOiJjaWhtdmxhNTIwb25zdHBsejk0NGdhODJhIn0.2-F2hS_oTZenAWc0BMf_uw'
      
    //Setup our Leaflet map using Mapbox.js
    var map = L.mapbox.map('map', 'mapbox.satellite')
    .setView([22.147709, -15.783053], 3);
    
    function project(featureObject){
      var coordinates = featureObject.geometry.coordinates;
      var reverse = [coordinates[1], coordinates[0]]
      var point = map.latLngToLayerPoint(L.latLng(reverse));
			
      return point;
    }
    
    // Setup our svg layer that we can manipulate with d3
    var svg = d3.select(map.getPanes().overlayPane)
      .append("svg");
    var g = svg.append("g").attr("class", "leaflet-zoom-hide");
    
    d3.json("ebola.json", function(err, data) {
      //console.log("data:", data)
 
      var dots = g.selectAll("circle").data(data.features)
      
      dots.enter()
        .append("circle")
      	.attr("fill", "white")
      	.attr("stroke-width", 2)
      	.attr("stroke", "red")
      	.attr("visibility", "hidden")
      
      function update() {
        // We need to reposition our SVG and our containing group when the map
        // repositions via zoom or pan
        // https://github.com/zetter/voronoi-maps/blob/master/lib/voronoi_map.js
        var bounds = map.getBounds();
        var topLeft = map.latLngToLayerPoint(bounds.getNorthWest())
        var bottomRight = map.latLngToLayerPoint(bounds.getSouthEast())
        console.log(bounds, topLeft, bottomRight)
        svg.style("width", map.getSize().x + "px")
          .style("height", map.getSize().y + "px")
          .style("left", topLeft.x + "px")
          .style("top", topLeft.y + "px");
        g.attr("transform", "translate(" + -topLeft.x + "," + -topLeft.y + ")");

dots.attr({
          cx: function(d) { return project(d).x },
          cy: function(d) { return project(d).y },
          r: 5
        })
      
      }
      update();
      
      map.on("viewreset", function() {
        update();
      })
      map.on("move", update)

})
  </script>
</body>

https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js

https://api.mapbox.com/mapbox.js/v2.2.3/mapbox.js