code: function(pxBounds) {
          var top = Math.max(pxBounds.top, 0);
          var left = Math.max(pxBounds.left, 0);
          var bottom = Math.min(pxBounds.top + Math.abs(pxBounds.getHeight()),
                                this.ovmap.size.h - this.hComp);
          var right = Math.min(pxBounds.left + pxBounds.getWidth(),
                               this.ovmap.size.w - this.wComp);
          var width = Math.max(right - left, 0);
          var height = Math.max(bottom - top, 0);
          if(width < this.minRectSize || height < this.minRectSize) {
              this.extentRectangle.className = this.displayClass +
                                               this.minRectDisplayClass;
              var rLeft = left + (width / 2) - (this.minRectSize / 2);
              var rTop = top + (height / 2) - (this.minRectSize / 2);
              this.extentRectangle.style.top = Math.round(rTop) + 'px';
              this.extentRectangle.style.left = Math.round(rLeft) + 'px';
              this.extentRectangle.style.height = this.minRectSize + 'px';
              this.extentRectangle.style.width = this.minRectSize + 'px';
          } else {
              this.extentRectangle.className = this.displayClass +
                                               'ExtentRectangle';
              this.extentRectangle.style.top = Math.round(top) + 'px';
              this.extentRectangle.style.left = Math.round(left) + 'px';
              this.extentRectangle.style.height = Math.round(height) + 'px';
              this.extentRectangle.style.width = Math.round(width) + 'px';
          }
          this.rectPxBounds = new OpenLayers.Bounds(
              Math.round(left), Math.round(bottom),
              Math.round(right), Math.round(top)
          );
      }
docs: Method: setRectPxBounds
  Set extent rectangle pixel bounds.
  
  Parameters:
  pxBounds - {<OpenLayers.Bounds>}