code: function(layerNameToHighlight) {
  				var i, curNames = [], numLayers = svgCanvas.getCurrentDrawing().getNumLayers();
  				for (i = 0; i < numLayers; i++) {
  					curNames[i] = svgCanvas.getCurrentDrawing().getLayerName(i);
  				}
  
  				if (layerNameToHighlight) {
  					for (i = 0; i < numLayers; ++i) {
  						if (curNames[i] != layerNameToHighlight) {
  							svgCanvas.getCurrentDrawing().setLayerOpacity(curNames[i], 0.5);
  						}
  					}
  				} else {
  					for (i = 0; i < numLayers; ++i) {
  						svgCanvas.getCurrentDrawing().setLayerOpacity(curNames[i], 1.0);
  					}
  				}
  			}
docs: This function highlights the layer passed in (by fading out the other layers) if no layer is passed in, this function restores the other layers