//import fl.ik.*;

var tree:IKArmature = IKManager.getArmatureByName("Armature_1");
var bone:IKBone = tree.getBoneByName("ikBoneName6");

var tJ:IKJoint = bone.tailJoint;
var posT: Point=tJ.position;

var ikMover:IKMover = new IKMover(tJ, posT);

addEventListener(Event.ENTER_FRAME, onFrame);
function onFrame(event:Event){
    posT.x=mouseX;
    posT.y=mouseY;
    ikMover.moveTo(posT);
}

This will get me:
*** ERROR ***
error in IKNode::loadXML: TypeError: Error #1086: The name method only works on lists containing one item.
*** ASSERT failed ***
Could not find root node