problem with node orientation (solved)

Hello,
I would like to set the node orientation to identity and after find the same node orientation but my code don't run

Ogre::Quaternion l_Orientation = m_Node->getOrientation();

m_Node->setOrientation(Ogre::Quaternion::IDENTITY);
m_Node->_update(NULL,NULL);

...code without modify orientation (I just take size of AABB)...

m_Node->setOrientation(l_Orientation);
m_Node->_update(NULL,NULL);

if(l_Orientation != m_Node->getOrientation())
std::cout<<"different"<<std::endl;

And it's different!

Please help me to find the same orientation after modify.

No, It's not different, it's just that it sets a 180° rotation in -180° rotation so it's same !!!