code: function(theDiv, newOpacity) {
     
          var mozillaOpacity = newOpacity;
          var ieOpacity = 'alpha(opacity=' + newOpacity * 100 + ')';
          
          theDiv.style.opacity = mozillaOpacity;
          theDiv.style.filter = ieOpacity;
  
          var spanElements = theDiv.parentNode.getElementsByTagName("span");
          
          for (var currIdx = 0; currIdx < spanElements.length; currIdx++) {
              spanElements[currIdx].style.opacity = mozillaOpacity;
              spanElements[currIdx].style.filter = ieOpacity;
          }
  
      }
docs: This is a helper function to change the background
  opacity of <div> that has had Rico rounded corners added.
  
  See changeColor (above) for algorithm explanation
  
  @param {DOM} theDiv A child of the outer <div> that was
  supplied to the `round` method.
  
  @param {int} newOpacity The new opacity to use (0-1).