x = 0;
menu = thisComp.layer("Null 3").effect("Dropdown Menu Control")("Menu").value;

for (x; x <= time; x += 0.5) {
	if ((x - inPoint) % 2 == 0){
		switch(menu){
		case 1:
		transform.opacity = linear(time, x, x + 0.5, 100, 0);
		break;
		case 2:
		transform.opacity = easeOut(time, x, x + 0.5, 100, 0);
		break;
		case 3:
		transform.opacity = easeIn(time, x, x + 0.5, 100, 0);
		break;
		case 4:
		transform.opacity = ease(time, x, x + 0.5, 100, 0);
		break;
		};
	};
};