ActionScript 2.0 :: Navigating To A Specific Frame?

I have a back button that should take you back from the first frame of one url to the last frame of another. However I can't figure out how to do this. It always brings you to the beginning.

tried this:

on (release) {
getURL("about :history.back(-1)");
}

but this won't always work because they can get there from a menu so the last thing in the history will be that menu instead of the last page of the section before.

tried this:

if(back == "true"){
gotoAndPlay(27);
}

as the variable that is checked at the start of my movie to see if it was opened from another movie

and:

on(release) {
getURL("introduction2.html?back=true", "_self");
stopAllSounds();
}

and this on the back button from the other movie

basically i just need to figure out a way to navigate to a specific frame in a different url.