private function checkPatternIsValid($patternType, $pattern, $matchAttribute)
{
if ($patternType == 'exact' && substr($pattern, 0, 4) != 'http' && substr($matchAttribute, 0, 6) != 'event_' && $matchAttribute != 'title') {
throw new Exception(Piwik::translate('Goals_ExceptionInvalidMatchingString', array("http:// or https://", "http://www.yourwebsite.com/newsletter/subscribed.html")));
}
}