code: function (px) {
          if ((px != null) && (this.icon != null)) {
              this.icon.moveTo(px);
          }           
          this.lonlat = this.map.getLonLatFromLayerPx(px);
      }
docs: Method: moveTo
  Move the marker to the new location.
  
  Parameters:
  px - {<OpenLayers.Pixel>|Object} the pixel position to move to.
  An OpenLayers.Pixel or an object with a 'x' and 'y' properties.