if (aItem == indexIsupports)
if (aItem == indexIsupports.get())
nsRangeList::RemoveItem(nsISupports *aItem){  if (!mRangeArray)    return NS_ERROR_FAILURE;  if (!aItem )    return NS_ERROR_NULL_POINTER;  for (PRUint32 i = 0; i < mRangeArray->Count();i++)  {    nsCOMPtr<nsISupports> indexIsupports = dont_AddRef(mRangeArray->ElementAt(i));    if (aItem == indexIsupports)    {      mRangeArray->RemoveElementAt(i);      return NS_OK;    }  }  return NS_COMFALSE;}