Leaflet Select Feature by hovering complete

HTML

<script src="http://leafletjs.com/examples/us-states.js"></script>
<script src="http://cdn.leafletjs.com/leaflet-0.7.3/leaflet.js"></script>
<link rel="stylesheet" href="http://cdn.leafletjs.com/leaflet-0.7.3/leaflet.css">
<div id="map"></div>

CSS

#map {
  height: 500px;
  margin-top: 10px;
}

#montana {
  background: rgba(255, 255, 0, 0.7);
  padding: 3px;
  cursor: pointer;
}

.info {
  padding: 6px 8px;
  font: 14px/16px Arial, Helvetica, sans-serif;
  background: white;
  background: rgba(255, 255, 255, 0.8);
  box-shadow: 0 0 15px rgba(0, 0, 0, 0.2);
  border-radius: 5px;
}

.info h4 {
  margin: 0 0 5px;
  color: #777;
}

.legend {
  text-align: left;
  line-height: 18px;
  color: #555;
}

.legend i {
  width: 18px;
  height: 18px;
  float: left;
  margin-right: 8px;
  opacity: 0.7;
}

JavaScript

var test, highlighted_feature;

var map = L.map('map').setView([20.5937, 78.9629], 4);

L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {
  attribution: '&copy; <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
}).addTo(map);

function getColor(d) {
  return d > 1000 ? '#800026' : d > 500 ? '#BD0026' : d > 200 ? '#E31A1C' : d > 100 ? '#FC4E2A' : d > 50 ? '#FD8D3C' : d > 20 ? '#FEB24C' : d > 10 ? '#FED976' :
    '#FFEDA0';
}

function style(feature) {
  return {
    weight: 2,
    opacity: 1,
    color: 'white',
    dashArray: '3',
    fillOpacity: 0.7,
    fillColor: getColor(feature.properties.density)
  };
}

function highlightFeature(e) {
  var layer = e.target || e;

  layer.setStyle({
    weight: 5,
    color: '#666',
    dashArray: '',
    fillOpacity: 0.7
  });

  if (!L.Browser.ie && !L.Browser.opera) {
    layer.bringToFront();
  }
}


var geojson;

function resetHighlight(e) {
  geojson.resetStyle(e.target || e);
}

function onEachFeature(feature, layer) {
  layer._polygonId = feature.id;
  layer.on({
    mouseover: highlightFeature,
    mouseout: resetHighlight
  });
}

geojson = L.geoJson(statesData, {
  style: style,
  onEachFeature: onEachFeature
}).addTo(map);


map.attributionControl.addAttribution('Population data &copy; <a href="http://census.gov/">US Census Bureau</a>');

// Top right legend control
    var legend = L.control({
      position: 'topright'
    });

    legend.onAdd = function(map) {
      var div = L.DomUtil.create('div', 'info legend'),
        grades = [0, 10, 20, 50, 100, 200, 500, 1000],
        from, to, span, color, text;

      for (var i = 0; i < grades.length; i++) {
        from = grades[i]; // Zahlen setzen 
        to = grades[i + 1];

        span = document.createElement("span");
        span.classList.add("legendItem");
        span.dataset.from = from;
        span.dataset.to = to;

        color = document.createElement("i");
        color.style.background = getColor(from + 1);

       ...