Google Maps +ol2+draw

HTML

<link rel="stylesheet" href="http://dev.openlayers.org/releases/OpenLayers-2.13.1/theme/default/style.css">
<script src="http://dev.openlayers.org/releases/OpenLayers-2.13.1/lib/OpenLayers.js"></script>
<script src="http://maps.google.com/maps/api/js?v=3&amp;sensor=false"></script>
<link rel="stylesheet" href="http://dev.openlayers.org/releases/OpenLayers-2.13.1/examples/style.css">
 <div id="map" ></div>
<button id="draw_btn" >Draw</button>

CSS

#map{
    width: 500px;
    height: 320px;
}

JavaScript

var map;

function init() {
//Initializez harta cu 4 layere Google Earth
    map = new OpenLayers.Map('map', {
    projection: 'EPSG:3857',
    layers: [
        new OpenLayers.Layer.Google(
            "Google Physical",
            {type: google.maps.MapTypeId.TERRAIN}
        ),
        new OpenLayers.Layer.Google(
            "Google Streets", // the default
            {numZoomLevels: 22}
        ),
        new OpenLayers.Layer.Google(
            "Google Hybrid",
            {type: google.maps.MapTypeId.HYBRID, numZoomLevels: 20}
        ),
        new OpenLayers.Layer.Google(
            "Google Satellite",
            {type: google.maps.MapTypeId.SATELLITE, numZoomLevels: 22}
        )
    ],
    center: new OpenLayers.LonLat(13.17, 55.70)
        // Google.v3 uses web mercator as projection, so we have to
        // transform our coordinates
        .transform('EPSG:4326', 'EPSG:3857'),
    zoom: 6,
    scales: [5000, 10000, 25000, 30000, 50000],
    units: 'm',
    });
    
    //click handler
    document.getElementById("draw_btn").onclick = devDraw;
    }

init();


function devDraw()
{

var x = new OpenLayers.Layer.Vector("one");
var p = new OpenLayers.Control.DrawFeature(x,                               OpenLayers.Handler.Polygon);
map.addLayer(x);
  
map.addControl(p);
p.activate();

}