Tha actual attack function

function CrossbowImage::onFire(%this, %obj, %slot)
{
   %projectile = %this.projectile;

   // Decrement inventory ammo. The image's ammo state is update
   // automatically by the ammo inventory hooks.
   %obj.decInventory(%this.ammo,1);

   // Determine initial projectile velocity based on the 
   // gun's muzzle point and the object's current velocity
   %muzzleVector = %obj.getMuzzleVector(%slot);
   %objectVelocity = %obj.getVelocity();
   %muzzleVelocity = VectorAdd(
      VectorScale(%muzzleVector, %projectile.muzzleVelocity),
      VectorScale(%objectVelocity, %projectile.velInheritFactor));

   // Create the projectile object
   %p = new (%this.projectileType)() {
      dataBlock        = %projectile;
      initialVelocity  = %muzzleVelocity;
      initialPosition  = %obj.getMuzzlePoint(%slot);
      sourceObject     = %obj;
      sourceSlot       = %slot;
      client           = %obj.client;
   };
   MissionCleanup.add(%p);
   return %p;
}

datablock ShapeBaseImageData(CrossbowImage)
{
        ...
// Fire the weapon. Calls the fire script which does 
   // the actual work.
   stateName[3]                     = "Fire";
   stateTransitionOnTimeout[3]      = "Reload";
   stateTimeoutValue[3]             = 0.2;
   stateFire[3]                     = true;
   stateRecoil[3]                   = LightRecoil;
   stateAllowImageChange[3]         = false;
   stateSequence[3]                 = "Fire";
   [b]stateScript[3]                   = "onFire";[/b]
   stateSound[3]                    = CrossbowFireSound;
         ...
}