[SOLVED] remove the collision?

hi, i have a problem in removing the collision.
i make racing game, and for the 1st stage i add a collision to all object in the 1st stage.
this is the code that i use to add the collision

SceneNode* bodyNode = mSceneMgr->getSceneNode(bodyName);
Vector3 currPos = bodyNode->getPosition();
Quaternion currOrient = bodyNode->getOrientation();

OgreNewt::Collision* col = new OgreNewt::CollisionPrimitives::TreeCollision( m_World, bodyNode, false );
OgreNewt::Body* bod = new OgreNewt::Body( m_World, col );
delete col;

bod->attachToNode(bodyNode);
bod->setPositionOrientation(currPos, currOrient);


and if i change the stage, the object collision from the old stage is not gone.
am i need to destroy the collision for all objects in the old stage?
how to destroy the collision?

thx for the help

easy way:

1. delete the old body from the old level.
2. make a new body from the new level.



another way:
1. build a new collision object from the new level.
2. set the collision for the body with setCollision().
3. delete the old collision object.

thx for the way to do remove the collision.
but i don't know to do that in the program.
can you give me code to delete the collssion?
b'coz i don't know how to delete that from the program.
i have try to delete that but it's not work at all

i can delete the body right now
just see this http://www.ogre3d.org/phpBB2addons/view ... 2156#32156