parent = fgWindowByID( parentID );
freeglut_return_val_if_fail( parent != NULL, 0 );
window = fgCreateWindow( parent, "", x, y, w, h, GL_FALSE, GL_FALSE );
parent = fgWindowByID( parentID );
freeglut_return_val_if_fail( parent != NULL, 0 );
window = fgCreateWindow( parent, "", x, y, w, h, GL_FALSE, GL_FALSE );