Dropdown menu HELP

hi
i have a drop down menu wich is a movie clip (inside it are the buttons).
now when i wrote the actionscrip for the buttons while the menu is on a different page, i made it work just fine. if i am on the home page and i press on each button of the drop down menu, i do get the right page i ask for.
but when i try to write the code to the same drop down menu buttons when i am on the same page (that is, i am on the about page with the history section shown) and i press on the education button, the history page does not go away.
now, each page is an external movie. and i used this kind of code:
on (release) {
//now i tell the other pages on the timeline to disappear//
_root.placeholderHistory._visible=false;
//it is _root since it is a movie dropdown menu,so the button is inside a movie//
//now i tell the right page to load//
loadMovie(“education.swf”,“placeholderEducation_mc”);

i have tried to do everything i know in order to tell the first placeholder to disappear (alpha,clear and so no) but nothing works.

what to do?

sorry that i do not load the movie since i do not know how.