code: function() {
  
          var size = new OpenLayers.Size(this.div.clientWidth, 
                                         this.div.clientHeight);
  
          if (size.w == 0 && size.h == 0 || isNaN(size.w) && isNaN(size.h)) {
              size.w = this.div.offsetWidth;
              size.h = this.div.offsetHeight;
          }
          if (size.w == 0 && size.h == 0 || isNaN(size.w) && isNaN(size.h)) {
              size.w = parseInt(this.div.style.width);
              size.h = parseInt(this.div.style.height);
          }
          return size;
      }
docs: Method: getCurrentSize
  
  Returns:
  {<OpenLayers.Size>} A new <OpenLayers.Size> object with the dimensions
  of the map div