code: function(marker) {
          var px = this.map.getLayerPxFromLonLat(marker.lonlat);
          if (px == null) {
              marker.display(false);
          } else {
              if (!marker.isDrawn()) {
                  var markerImg = marker.draw(px);
                  this.div.appendChild(markerImg);
              } else if(marker.icon) {
                  marker.icon.moveTo(px);
              }
          }
      }
docs: Method: drawMarker
  Calculate the pixel location for the marker, create it, and
  add it to the layer's div
  
  Parameters:
  marker - {<OpenLayers.Marker>}