Loading xml elements with dinamyc x/y

hey there
im having a big trouble
i cant resolve this script
i took this from a fla sample

menuXml = new XML();
menuXml.ignoreWhite = true;
menuXml.onLoad = function(success) {
if (success) {
var menuItem = menuXml.firstChild.childNodes;
for (var i = 0; i<menuItem.length; i++) {
Nombre = menuItem*.firstChild.nodeValue;
Link = menuItem*.attributes.url;
attachMovie(“item_mc”, “item_mc”+i, i);
_root[“item_mc”+i]._x = 110i;
_root[“item_mc”+i]._y = 0
_root[“item_mc”+i].etiqueta_txt.text = Nombre;
_root[“item_mc”+i].Link = Link;
getURL(this._parent.Link); }

this load a xml file, with text and a url

_root[“item_mc”+i]._x = 110i;
_root[“item_mc”+i]._y = 0

this part gives a y position to the loaded element
but, this is a standard distance between all the elements
i need that the _y position will be according / next to the last element, not always with the same distance
any clue?