ActionScript 2.0 :: Disable Buttons In MC When Another MC Plays?

I am building my online portfolio and basically you scroll through my work (you may have noticed another thread about this lol) and then you click on an image which represents the different work that i have done. This opens an "info box" with a few more screen shots of that project and some text about it. This all works great, but what i need is when the "info box is opened (loaded externally), the other buttons etc on the stage need to be disabled because the info box loads in a layer above everything else. When the infobox is closed, the buttons etc need to be enabled again so i cant just put the code in the onRelease function which activates the infobox as this will permanently disable everything. I was thinking maybe I can set up some variables so it can detect whether the infobox is opened or closed depending on the value of the variable but I have found it hard to reference the variables properly.

My portfolio is currently online - www.theo-nicolaou.co.uk - but it is one year old, buggy, slow and needs updating as i have more work to show. That is why I am rebuilding - mainly the structure and a few design changes. If you go to the link, click on portfolio, and then click on one of the circular buttons under the black square, and then click the image in the square you will see the "info box" and you will notice that any buttons underneath are disabled until the box is closed.

To activate the infobox, an image (i call it a thumbnail" is clicked, for example, "DG_thumb":

Code:
DG_thumb.onRelease = function() {
_root.holder_mc.infobox_holder.loadMovie("DG_infoBox.swf", "start");
}

the portfolio page itself is a separate .fla (portfolio.fla) which is loaded into a main fla which has an empty MC called holder_mc. The instance name "infobox_holder" is in the portfolio.fla file and that is what it is loaded into when the thumbnail is clicked. The thumbnail itself is within a MC called webList (in this case) which is within a MC called portfolioList. This is on the main timeline of portfolio.fla so i guess the path would be (though maybe i am wrong):

Code:
_root.holder_mc.portfolioList.webList.DG_thumb

however this doesnt seem to make any difference and it is still enabled even if i use enabled = false;I have also tried using _parent. but that doesnt work either.I also need to disable the circular group of buttons which are within a MC on the main timeline of portfolio.fla called "circles". They all have instance names, so in the case of the work i call DG, it would be "DG_button".