Unknown Quality

var box:b2BoxDef = new b2BoxDef();
box.extents.Set(30/m_physScale, 10/m_physScale);
box.density = 1;

var bd:b2BodyDef = new b2BodyDef();
bd.AddShape(box);
bd.position.Set(50 / m_physScale, 100 / m_physScale);
var body1:b2Body =  m_world.CreateBody(bd);

bd = new b2BodyDef();
bd.AddShape(box);
bd.position.Set(100 / m_physScale, 100 / m_physScale);
var body2:b2Body = m_world.CreateBody(bd);

var jd:b2RevoluteJointDef = new b2RevoluteJointDef();
jd.anchorPoint.Set(75/m_physScale , body1.m_position.y );
jd.body1 = body1;
jd.body2 = body2;
m_world.CreateJoint(jd);