static public function getSecondDomain($domain=null)
	{
	    $domain = !empty($domain) ? $domain : (isset($_SERVER['HTTP_HOST']) ? $_SERVER['HTTP_HOST'] : null);
	    $n = preg_match('/([^.]*\.)?([^.]*\.)?\w+\.\w+$/', $domain, $matches);
	    return $domain && isset($matches[2]) ? $matches[2] : (isset($matches[1]) ? $matches[1] : '');
	}
static public function getSecondDomain($domain=null)
	{
	    $domain = !empty($domain) ? $domain : (isset($_SERVER['HTTP_HOST']) ? $_SERVER['HTTP_HOST'] : null);
	    $n = preg_match('/([^.]*\.)?([^.]*\.)?\w+\.\w+$/', $domain, $matches);
	    return $domain && isset($matches[2]) ? $matches[2] : (isset($matches[1]) ? $matches[1] : '');
	}
static public function getSecondDomain ( $ domain = null ) { $ domain = ! empty ( $ domain ) ? $ domain : ( isset ( $ _SERVER [ 'HTTP_HOST' ] ) ? $ _SERVER [ 'HTTP_HOST' ] : null ) ; $ n = preg_match ( '/([^.]*\.)?([^.]*\.)?\w+\.\w+$/' , $ domain , $ matches ) ; return $ domain && isset ( $ matches [ 2 ] ) ? $ matches [ 2 ] : ( isset ( $ matches [ 1 ] ) ? $ matches [ 1 ] : '' ) ; }
get second domain
@param  string $domain
@return string
get second domain