Trouble passing variable

I have looped item and window to use the same photo in two different places. I can't get the unique Id for the window loop clicked into the last line of code to control the alpha: "_root.project["window" + Id].pix._alpha = 100;" Is there a way to do? Any help is appreciated.
thanks
yogi b

for(i=0; i < gOverview.itemCount; i++){
_root.project["item"+i]._visible = true;
_root.project["item"+i].description = "<b>" + gOverview["proName"+i] + "</b>: " + gOverview["proDescription"+i];
_root.project["item"+i].Id = gOverview["proId"+i];
_root.project["item"+i].imageHolder.loadMovie(gOverview["proImage"+i]);
_root.project["window"+i].pix.loadMovie(gOverview["proImage"+i]);


_root.project["item"+i].item_btn.onPress = function () {
itemClicked (this._parent.Id);
for (var i = 0; i < gOverview.itemCount; ++i) {
_root.project["item"+i].imageHolder._alpha = 100;
_root.project["window"+i].pix._alpha = 0;

}
this._parent.imageHolder._alpha = 50;
_root.project["window" + Id].pix._alpha = 100;


}

}