Load XML into flash from flashvar set in HTML?

so here’s where I load my XML into FLash…

_global.xmlFinishedLoading = false;

my_xml = new XML();
my_xml.ignoreWhite = true;
my_xml.onLoad = function(sucess) {
	   if (sucess) {
			trace ("XML loaded");
			_global.xmlStuff = new XML(this);
			//gotoAndPlay(2);
        } else {
			_root.debug.text = "couldn't load XML file";
		}
};


_global.baseURL = "";
my_xml.load(_global.baseURL + "slideshow.xml");

I want the .xml file to be a variable I set from the HTML in the OBJECT tag, so that I can make it more dynamic. How?

my_xml.load(_global.baseURL + "slideshow.xml");