Difficulties with attachMovie

So I got the idea recently to build an mp3 playing application that used a playlist loaded from an XML file. I just want it to get to where the program reads how many songs are in the XML, makes that many buttons with the song name on them, etc. so that when you click the button the song will play. I’m fairly clear on the sound and XML aspects, but I’m having trouble getting this loop to work:

var btn_height:Number = 0;
var button_name = [];
for (i=0; i<4; i++) {
button_name* = “songbtn” + i;
_root.attachMovie(“song_btn”, “songbtn” + i, 10);
btn_height += 24;
button_name*._y = btn_height;
trace(“success”);
};

When I run this, what I get is one button at (0,0) when what I want is five buttons one on top of the other. Any advice?

also, this is my first post, so let me know if I’m missing any information here.