Flash Movie Clip inside Loader

Hello, i’m Samad from India, Now i’m with a website work. I want your help.
My level is,
I have a movieclip named button_mc, all the buttons are placed inside it.
I want only that when any button rollover instance i want to go to play the certain key frames in the movie clip button_mc.
For example in my button_mc i have buttons llike product_btn, graphic_btn etc when the instance i release my mouse on product_btn i want to go inside button_mc frame25.
I used the script like,
button_mc.product_btn.onRelease = function(){
But its not working please suggest me the right way