public static function createSlug($string)
	{
		// remove all accent characters
		$string = self::remove_accents($string);

		// lowercase
		$string = strtolower($string);

		// replace all characters except letters and numbers to dashes
		$slug = preg_replace('/[^A-Za-z0-9-]+/', '-', $string);

		// deep replace double dashes
		while(strpos('--', $slug))
		{
			$slug = str_replace('--', '-', $slug);
		}

		// trim dashes at start and end
		$slug = trim($slug, '-');

		return $slug;
	}