Need help

1

First off, i am just a student with practically no programming expierience so, well, my code is probally completey messed up. I just started flash and since im bad at animating, i decided to try making a game.
My problem is i followed kirupa’s tutorial “Game How to Fire”, but i wanted to make it so instead of clicking to fire you press shift. It didnt work so i basically mixed and matched code untill it worked.
Unfortunately, for some reason if you press shift the bullet gets relocated to the plane and fires again, instead of creating another bullet and firing it.
Oh yeah, and the bullet doesnt disappear when it reaches the point i set it to with “removemovieclip”.
Also, something that isnt necessary but i would like to do it, is when you hold down shift i want it to repeatidly fire shots instead of not firing untill shift is released.
Heres the code i put on the bullet:

onClipEvent (load) {
 this._visible = 0
}
onClipEvent (enterFrame) {
 planedir =  _root.plane._rotation*1.111111
 if (Key.isDown(Key.SHIFT)) {
        _root.hot = 1
   _root.i += random(10)+1;;
   duplicateMovieClip
    (_root.bullet, "bullet"+i, i); command
    this._x = _root.plane._x
       this._y = _root.plane._y
 }
 if (this != _level0.bullet) {
  if (_root.hot == 1) {
   this._rotation = _root.plane._rotation
   this._x += 50;
   this._y += planedir;
   this._visible = 1;
 if (this._x>550) {
 this.removeMovieClip();
 }
  }
 }
}