Movieclip onRelease

It’s been a long time since I did some flash and now I’m stuck on something that should be easy…

I have a movieclip and I load a png file into it.
then I want to put an onRelease on it and this won’t work… my cursor doesn’t even change into a hand…
Am I missing somthing here?

_root.createEmptyMovieClip(“hosting_mc”, 5);
loadMovie("…/images/hosting.png", hosting_mc);

_root.hosting_mc.onRelease = function(){
getURL(“”, “_blank”);
trace(_root.hosting_mc) // --> this gives me “_level0.hosting_mc”