Hi ! I have a game and i'm trying to make changes when a thing happens

I want to do this, when the "caught" flies rise up to "50" increase the value
for the flies falling frame per frame

so I tried this:

(I post the last part of the code because maybe my mistake could be there)

Code:
function crearID():void{
	var enemigo:Cayendo=new Cayendo()
	enemigo.y=-50;
	enemigo.x=Math.random()*stage.stageWidth;
	enemigo.addEventListener(Event.ENTER_FRAME,dropEnemy);
	addChild(enemigo);
}

function dropEnemy(e:Event):void{
	var mc:Cayendo=Cayendo(e.target);
//THIS IS WHAT I WANT TO CHANGE WHEN atrapadasText.text=="50"
	mc.y+=10 
//ONLY CHANGING mc.y+=10       to     mc.y+=60 IS WHAT I WANT
	if(mc.hitTestObject(agarrador)){
		atrapadas(mc);
	}else if(mc.y>stage.stageHeight){
		erradas(mc);
/*THIS IS HOW I MEANT TO DO IT
	if(atrapadasText.text=="50"){
         mc.y+=60
	}*/
	
}
function atrapadas(mc:Cayendo):void{
	mc.removeEventListener(Event.ENTER_FRAME,dropEnemy);
	removeChild(mc);
	atrapadasText.text=String(Number(atrapadasText.text)+1);
	if(atrapadasText.text=="50"){
		nivel2.gotoAndPlay(1);
	}
}
function erradas(mc:Cayendo):void{
	mc.removeEventListener(Event.ENTER_FRAME,dropEnemy);
	removeChild(mc);
	erradasText.text=String(Number(erradasText.text)+1);
	if(erradasText.text=="5"){
		gameOver();
}
}

function gameOver():void{
	score=Number(atrapadasText.text);
	removeChild(agarrador);
	clearInterval(crearIDenemigo);
	removeChild(atrapadasText);
	removeChild(erradasText);
	while(numChildren>0){
	getChildAt(0).removeEventListener(Event.ENTER_FRAME,dropEnemy);
	removeChildAt(0);
	}
	stage.removeEventListener(KeyboardEvent.KEY_DOWN, presionoTecla);
	stage.removeEventListener(KeyboardEvent.KEY_UP, sueltoTecla);
	stage.removeEventListener(Event.ENTER_FRAME , mover);
	gotoAndStop("game over");
	Mouse.show();
}
iniciarJuego();
what i'm doing wrong'?