title: getUserMedia Error webRTC
body: <p>I'm starting with webRTC and am trying to access to my camera, however, the code doesn't work, although there is no mistakes in it.</p>
  
  <p>The code is:</p>
  
  <pre><code>navigator.getUserMedia = ( navigator.getUserMedia ||           
                                 navigator.webkitGetUserMedia || navigator.mozGetUserMedia 
                              || navigator.msGetUserMedia);
  if (navigator.getUserMedia){
      var constrains ={video:true};
      function successCallback(localMediaStream){
          var video = document.querySelector("video");
          window.stream = localMediaStream;
          video.src = window.URL.createObjectURL(localMediaStream);
          video.onloadedmetadata =function(e){
              video.play();
          }
      }
      function errorCallback(error){
          console.log("Error: ",error);
      }
      navigator.getUserMedia(constrains,successCallback,errorCallback);
  }else{
      alert('Sorry, the browser you are using doesn\'t support getUserMedia');
  }
  </code></pre>
  
  <p>Can you help me please?</p>