title: The correct way to hide a polyline?
body: <p>I´ve a function that show a polyline on a map, this part is working, now I want to implement a function that hides the polyline, but I can´t find my mistake, thanks in advance.</p>
  
  <pre><code>function cargaMapaCYL(mapa, varControl){
      var limite = null; 
      limite = [
          new google.maps.LatLng(42.49956716,-7.019005501),
          new google.maps.LatLng(42.49947126,-7.029286373),
          new google.maps.LatLng(42.50904062,-7.049299123),
          new google.maps.LatLng(42.50722622,-7.069103626),
          new google.maps.LatLng(42.50452387,-7.000150672),
          new google.maps.LatLng(42.49348015,-6.983058917),
          new google.maps.LatLng(42.49843269,-6.971666546),
          new google.maps.LatLng(42.51765791,-6.956909023),
          new google.maps.LatLng(42.52010069,-6.927429186),
          new google.maps.LatLng(42.50992238,-6.914231493),
          new google.maps.LatLng(42.50096695,-6.879679821),
          new google.maps.LatLng(42.48775868,-6.857775832),
          new google.maps.LatLng(43.23907504,-3.293216584)], "#000000", 5);
  
      var contorno= new google.maps.Polyline({
          path: limite,
          strokeColor: "#000000",
          strokeOpacity: 1.0,
          strokeWeight: 2
      });
      if(varControl==true){
          contorno.setMap(mapa);
      }
      if(varControl==false){
          contorno.setMap(null);
      }
  }
  </code></pre>