code: function(px) {
          var newPx = OpenLayers.Popup.Anchored.prototype.calculateNewPx.apply(
              this, arguments
          );
  
          newPx = newPx.offset(this.positionBlocks[this.relativePosition].offset);
  
          return newPx;
      }
docs: Method: calculateNewPx
  Besides the standard offset as determined by the Anchored class, our
  Framed popups have a special 'offset' property for each of their
  positions, which is used to offset the popup relative to its anchor.
  
  Parameters:
  px - {<OpenLayers.Pixel>}
  
  Returns:
  {<OpenLayers.Pixel>} The the new px position of the popup on the screen
  relative to the passed-in px.