getURL - undefined prob

hello:
i have a problem with getURL in a dynamically generated menu, when i clicked the button it shows undefined in the browser. but when i trace it, it shows the proper URL. check the code below. thanks in advance.

heirarchy:
content_mc -> bg_mc -> nav_btn

script:
var buttonNames:Array = [“name1”,“name2”,“name3”];
var btnURL:Array = [“URL1”,“URL2”,“URL3”];
var spacing:Number = content_mc.bg_mc._height + 1;
content_mc.bg_mc._visible = false;
var numberofButtons:Number = buttonNames.length;
var i:Number = -1;

while (++i < numberofButtons) {
var name:String = “item” + i;
content_mc.bg_mc.duplicateMovieClip(name, i);
content_mc[name].name_txt.text = buttonNames*;
content_mc[name]._x = 0;
content_mc[name]._y = i * spacing;
//trace(buttonNames*);
trace (btnURL*);
content_mc[name].nav_btn.onRelease = function () {
getURL (btnURL*,"");
};
}