CEventCalendar::GetOwnerName

static function GetOwnerName($arParams)
{
	if($arParams['ownerType'] == 'USER')
	{
		// Get user name
		$dbUser = CUser::GetByID($arParams['ownerId']);
		if (!$arUser = $dbUser->Fetch())
			return;
		$ownerName = $arUser["NAME"]." ".$arUser["LAST_NAME"];
	}
	else if($arParams['ownerType'] == 'GROUP')
	{
		// Get group name
		if (!$arGroup = CSocNetGroup::GetByID($arParams['ownerId']))
			return;
		$ownerName = $arGroup["NAME"];
	}
	else
	{
		// Get iblock name
		$rsIblock = CIBlock::GetList(array(), array("ID"=>$arParams['iblockId'], "CHECK_PERMISSIONS" => 'N'));
		if(!$arIblock = $rsIblock->Fetch())
			return;
		$ownerName = $arIblock['NAME'];
	}

	return $ownerName;
}