GetItemInSlot

// Get the object which is in oCreature's specified inventory slot
// - nInventorySlot: INVENTORY_SLOT_*
// - oCreature
// * Returns OBJECT_INVALID if oCreature is not a valid creature or there is no
//   item in nInventorySlot.
object GetItemInSlot(int nInventorySlot, object oCreature=OBJECT_SELF);