Referencing something in _root not working

I have a class ‘resizingObject’, with a method ‘addFunction()’, which is instantiated in _root as ‘resizer’ (im certain of this - ive checked in the debug - variables list)

I then have another class, ‘layerObject’, that i want to be able to call the ‘addFunction()’ method - so inside the layerObject i tried _root.resizer.addFunction(), _level0.resizer.addFunction() and all manner of other business but to no avail…even an attempt to trace _root.resizer returns undefined.

why cant i acces the resizer instance of the resizingObject?