Level control

Hi!! I have a tricky( at least for me) one… I have a couple of buttons on a movie in level 0, and those buttons load movies right on top of this one but to level 1… how can i disable buttons on level 0 as soon as level 1 loads, and vice versa, need to enable them when i press the button on level 1 that unloads this movie… i’m getting desperate by now!!!

thanks for any help and replys!!