How can I share one JS function within all my transformations?

Hi!

I have one function that I use in a JS objet an this JS objet is present in a lot of my transformations.

I want to know if it is possible to "declare" this function somewhere and then "call" it from any JS objet where I need it.

The major need is that so I can change ONE AND ONLY function (and not the 48 items as it is ;-) )

Thanck's