Why one "for" loop working, other not?

programming flash
1

Why does the first loop work but not the other?

 
for (var i:uint =0; i<8; i++)//This one works.
{
 this["popUp" + i].addEventListener(MouseEvent.CLICK, handleClick);
 this["popUp" + i].buttonMode = true;
 this["popUp" + i].mouseChildren = false;
 this["popUp" + i].useHandCursor = true;
}
 
for (var n:uint = 0; i<8; i++)//This one does not work.
{
 this["popUp" + n + "hl"].visible = false;
 /*popUp0hl.visible = false;
 popUp1hl.visible = false;
 popUp2hl.visible = false;
 popUp3hl.visible = false;
 popUp4hl.visible = false;
 popUp5hl.visible = false;
 popUp6hl.visible = false;
 popUp7hl.visible = false;*/
}