code: function(map) {
          OpenLayers.Layer.prototype.setMap.apply(this, arguments);
          
          this.pane.style.zIndex = parseInt(this.div.style.zIndex) + 1;
          this.pane.style.display = this.div.style.display;
          this.pane.style.width="100%";
          this.pane.style.height="100%";
          if (OpenLayers.BROWSER_NAME == "msie") {
              this.pane.style.background = 
                  "url(" + OpenLayers.Util.getImageLocation("blank.gif") + ")";
          }
  
          if (this.isFixed) {
              this.map.viewPortDiv.appendChild(this.pane);
          } else {
              this.map.layerContainerDiv.appendChild(this.pane);
          }
  
          // once our layer has been added to the map, we can load it
          this.loadMapObject();
      
          // if map didn't load, display warning
          if (this.mapObject == null) {
              this.loadWarningMessage();
          }
      }
docs: Method: setMap
  Set the map property for the layer. This is done through an accessor
  so that subclasses can override this and take special action once
  they have their map variable set.
  
  Parameters:
  map - {<OpenLayers.Map>}