Attached MC instance names disappear

programming flash
1

I have a small problem over here. I’ve attach an MC with attachMovie() and the instance names that were inside of that MC disappeared.

getWinLogin.onRelease = function() {
	zona.createEmptyMovieClip("winLogin", getNextHighestDepth());
	zona.attachMovie("winLogin2", "winLogin", getNextHighestDepth());
}
zona.winLogin.login.onRelease = function() {
	trace(zona.winLogin.fieldUser);
}

Any ideas what the problem is?

Thank you in advance.

2 
getWinLogin.onRelease = function() {
    zona.createEmptyMovieClip("emptyClip", zona.getNextHighestDepth());
    zona.emptyClip.attachMovie("winLogin2", "winLogin", zona.emptyClip.getNextHighestDepth());
}
zona.emtyClip.winLogin.login.onRelease = function() {
    trace(zona.emtyClip.winLogin.fieldUser);
}

you forgot that the winLogin was inside the emptyMovieClip you created