title: ReferenceError: OpenLayers is not defined while using osm layer
body: <p>I am using openLayer3 and osm for the map now trying to draw polylines on the the map when i do so</p>
  
  <p>1:the poly lines are not displayed and also i am getting the error in browser has 
  ReferenceError: OpenLayers is not defined </p>
  
  <p>Below is the following code:</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
  &lt;head&gt;
      &lt;title&gt;Rotation example&lt;/title&gt;
  &lt;/head&gt;
  &lt;body&gt;
  &lt;div id="map" class="map"&gt;&lt;/div&gt;
  &lt;script src="http://openlayers.org/en/v3.11.2/build/ol.js"&gt;&lt;/script&gt;
  &lt;script&gt;
  &lt;!-- code to draw the polyline on the map--&gt;
  
      var lineLayer = new OpenLayers.Layer.Vector("Line Layer");
      map.addLayer(lineLayer);
      map.addControl(new OpenLayers.Control.DrawFeature(lineLayer, OpenLayers.Handler.Path));
      var points = new Array(
              new OpenLayers.Geometry.Point(103.987305, 1.355333),
              new OpenLayers.Geometry.Point(103.987262, 1.354432)
      );
  
      var line = new OpenLayers.Geometry.LineString(points);
      var style = {
          strokeColor: 'white',
          strokeOpacity: 0.5,
          strokeWidth: 5
      };
      var lineFeature = new OpenLayers.Feature.Vector(line, null, style);
      lineLayer.addFeatures([lineFeature]);
  
      var map = new ol.Map({
          layers: [
              new ol.layer.Tile({
                  source: new ol.source.OSM()
              }),
            lineLayer 
          ],
  
          target: 'map',
          controls: ol.control.defaults({
              attributionOptions: /** @type {olx.control.AttributionOptions} */ ({
                  collapsible: false,
  
              })
          }),
          view: new ol.View({
              center: ol.proj.fromLonLat([103.986908, 1.353199]),
              rotation: 68*Math.PI/180,
              zoom: 18
          })
      });
  
  
  
  &lt;/script&gt;
  
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>I am  a newbie please say where i am going wrong</p>