protected function convertStringEncoding($string, $fromEncoding, $toEncoding) {
		$convertedString = null;
		if($string && $fromEncoding != $toEncoding) {
			$convertedString = @iconv($fromEncoding, $toEncoding . '//IGNORE', $string);
			if(!$convertedString && extension_loaded('mbstring')) {
				$convertedString = @mb_convert_encoding($string, $toEncoding, $fromEncoding);
			}
		}
		return $convertedString ?: $string;
	}