Space Shooter

I searched for about 2 hours and finally figured out part of the code i need (i think). Basically what i need is for my “spaceship” to have an alternate fire every 5000 points. Currently i have

if (_root.score >=5000)
if (Key.isDown(Key.ALT)) {
i++;
if(timer >= 0)
_root.attachMovie(“Bullet0”,“Bullet0”+i,_root.getNextHighestDepth());
_root[“Bullet0”+i]._x = Ship._x+3;
_root[“Bullet0”+i]._y = Ship._y;
timer =0;
}
I need it to only fire 10 times repeatedly every 5000 points. Help would be greatly appreciated.