[Swftools-common] access parameter passed through externallinkfunction

[matt cline]

is there a way to access the parameter(url) passed by externallink function? lets say i load a pdf2swf converted page into a player that contains externalinkfunction buttons....well i find those buttons like this:
            for(var i in _mc){
                if(_mc[i].__proto__ == Button.prototype){
                var mybutton:Button=_mc[i];
                trace(mybutton._name);
               }
            }

how can i get the url that button passes when clicked?  What im trying to do is show the url on hover.  I can raise an onRollOver event with the above, but accessing the buttons parameters is where im stuck...where is that stored? how is my external link function actually called? ie via hit test, Press, Release? ....thank you.