osg help

#ifdef _WIN32
#include <Windows.h>
#endif // _WIN32

#include <osgViewer/Viewer>
#include <osgDB/ReadFile>
#include <osgGA/GUIEventAdapter>
#include <osgViewer/ViewerEventHandlers>

int main()
{
　　osg::ref_ptr<osgViewer::Viewer> viewer = new osgViewer::Viewer;
　　osg::ref_ptr<osg::Node> node = new osg::Node;

　　node = osgDB :: readNodeFile ( "D : \\ Reference OSG \\ \\ library.OSGB the BIM \\");
　　viewer-> setSceneData (node.get ());
　　viewer-> setUpViewInWindow (200,200,700,500,0);
　　
　　// add an event to help
　　viewer-> addEventHandler (new osgViewer :: HelpHandler );

　　return viewer->run();
}