code: function (px) {
          if ((px != null) && (this.div != null)) {
              this.div.style.left = px.x + "px";
              this.div.style.top = px.y + "px";
          }
      }
docs: Method: moveTo
  Sets the left and top style attributes to the passed in pixel
  coordinates.
  
  Parameters:
  px - {<OpenLayers.Pixel>}