code: function(options) {
          OpenLayers.Control.Panel.prototype.initialize.apply(this, [options]);
          this.addControls([
            new OpenLayers.Control.Navigation(),
            new OpenLayers.Control.ZoomBox()
          ]);
      }
docs: Constructor: OpenLayers.Control.NavToolbar
  Add our two mousedefaults controls.
  
  Parameters:
  options - {Object} An optional object whose properties will be used
  to extend the control.