umm, here is the right code, and i would use an onClipEvent since its not a button:
onClipEvent(mouseup) {
getURL("http://www.yoursite.com", "_parent")
}
or a regulare on,
on(release) {
getURL("http://www.yoursite.com", "_parent")
}
there was no need for the press, release. and that was what screwed you over.
good luck!