void main()
{

object oPC = GetEnteringObject();

if (!GetIsPC(oPC)) return;

if (GetTag(GetItemInSlot(INVENTORY_SLOT_CLOAK, oPC)) == "MedusasShawl")
   return;

object oTarget;
oTarget = oPC;

ApplyEffectToObject(DURATION_TYPE_PERMANENT, EffectPetrify(), oTarget);

}