Setting object invisible on command

I am sure this script is out there somewhere and i am just to much of a moron to find it. I need a script that on chat command will turn a set of objects invisible and then visible again with a different chat command. It's for a massage table so we can RP putting on clean sheets. Can some one point me in the right direction. I will even pay for the script if not to much, kinda broke at the moment. I need the script to be able to be used by all my emplyee's, not just the owner.

ok never mind i found a window script from Adriana Caligari that works i am just trying to figure out how to get anyone to use it not just owner.

something like

integer gBooSwap;

default{
  state_entry(){
    llListen( 13, "", "", "change" );
  }

  listen( integer vIntNull, string vStrNull, key vKeyNull, string vStrCommand ){
    llSetAlpha( (gBooSwap = !gBooSwap), ALL_SIDES );
  }
}

/13 change
will swap the alpha on the single prim it's in (or the whole object if it's in the root)