Base::getOrigNameField

protected function getOrigNameField($name)
{
	$rewriteFields = $this->getRewriteFields();
	foreach ($rewriteFields as $origName=>$rewriteField)
	{
		$alias = $rewriteField['REFERENCE_FIELD'];
		if($name === $alias)
		{
			return $origName;
		}
	}
	return null;
}