Change saturation movieclip via actionscriptor color matrix?

programming flash
1

hi,

i was reading the help and discovered i can change the filters thru as, but can’t seem to figure out how to change the saturation.

I want my image to be black and white and go back to color upon rollover.
i have done it with a separate bw image but i think, at least, that it would reduce my file size by doing it with actionscript. is that true?

this is the code in help:

var myFilters = fl.getDocumentDOM().getFilters();
for(i=0; i < myFilters.length; i++){
    if(myFilters*.name == 'adjustColorFilter'){
        myFilters*.saturation = 0;
    }
}
fl.getDocumentDOM().setFilters(myFilters);

doesn’t work when set on mc.
don’t know where to insert my movie clip name???
do i need to do the color matrix? which is even more confusing.
is this the right code to use? or is there something simpler?
thanks
hope all is well