External swf doesnt load xml

1

I have a main swf [1] that loads an external swf [2] into it
In the external swf [2] there is a movieclip that when pressed loads some information from an XML file
when i try the external swf [2] it works fine but when i try it from the main swf [1] it doesnt work

here is the code for the movieclip

i tried putting _root. or this. but that didnt work

this.onRelease = function(){
    portfolio_xml.load('xml/portfolio4.xml');
}