onEnterFrame _alpha

Hello.

Iā€™m having a problem where I have three buttons and when I make rollOver above the first one, the second and third must stay with _alpha=10 but on enterframe to see the animation. When I rollOver the second button, the first and third must be affected by _alpha and so on.

My doubt is when I make this and move to another button befora the nem button _alpha is equal to 100, the alpha of the actual button stops :frowning:

PS:Sorry about my english, but I think you will understand better with the fla exemple in attachment.