How to make things fade out in ACS?

How would I make things such as monsters, weapons, ammo, etc fade out slowly? I know how to fade them in using this script:

script 999 (int thingID, int thingSpawn, int newTID)
{
   if(thingSpawn > 0)
   {
      Thing_SpawnFacing(thingID,thingSpawn,1,thingID);
   }

   int a = 0.1;
   int b = 0;
   ThingSound(thingID,"monster_spawn",127);
   Thing_Activate(thingID);
   SetActorProperty(thingID,APROP_RenderStyle,STYLE_Translucent);
   for(b = 1; b < 10; b++)
   {
      SetActorProperty(thingID,APROP_Alpha, a);
      a += 0.1;
      delay(2);
   } SetActorProperty(thingID,APROP_Alpha, 1.0);

   if(newTID > 0)
   {
   Thing_ChangeTID(thingID,newTID);
   }
}

But how would I reverse it and make the monster fade out and be removed from the map? Thank you for any help.

I'm not sure, but you can try this:

{
      SetActorProperty(thingID,APROP_Alpha, a);
      a -= 0.1;
      delay(2);
}
      Thing_Remove(thingID);

No, this instantly just removes the thing, or atleast the way I'm using it but thanks.