Changing alpha with AS (as included.. please look)

1

I’ve been trying to change an MCs alpha with actionscipt. the movies FPS is 30.

here’s the as:

[AS]
onClipEvent(load) {
var alpha = blue._alpha;
alpha = 50;
var forwardA = true;
var changeA = true;
}

onClipEvent(enterFrame) {
if(changeA) {
if(forwardA) {
if(alpha >= 0){
alpha++;
} else {
forwardA = false;
} // end alpha >= 0

     } else {
         if(alpha >= 100){
             alpha--;
         } else {
             forwardA = true;
         } // end alpha >=100
     } // end forwardA
 } // end changeA

}
[/AS]

whats wrong with my code? btw, “blue” is the MC that i want to change the alpha of, and this code is on that MC.