Added the usage report to the examples for when no arguments are passed

to the examples.

examples/osgpbuffer/osgpbuffer.cpp

@@ -585,7 +585,7 @@ int main( int argc, char **argv )
     osg::ArgumentParser arguments(&argc,argv);
     
     // set up the usage document, in case we need to print out how to use this program.
-    arguments.getApplicationUsage()->setCommandLineUsage(arguments.getProgramName()+" [options] filename ...");
+    arguments.getApplicationUsage()->setCommandLineUsage(arguments.getApplicationName()+" [options] filename ...");
     arguments.getApplicationUsage()->addCommandLineOption("-h or --help","Display this information");
     
 
@@ -615,6 +615,12 @@ int main( int argc, char **argv )
         return 1;
     }
     
+    if (arguments.argc()<=1)
+    {
+        arguments.getApplicationUsage()->write(std::cout,osg::ApplicationUsage::COMMAND_LINE_OPTION);
+        return 1;
+    }
+    
     // load the nodes from the commandline arguments.
     osg::Node* loadedModel = osgDB::readNodeFiles(arguments);