ftp_base::file_exists

	function file_exists($pathname) {
		$exists=true;
		if(!$this->_exec("RNFR ".$pathname, "rename")) $exists=FALSE;
		else {
			if(!$this->_checkCode()) $exists=FALSE;
			$this->abort();
		}
		if($exists) $this->SendMSG("Remote file ".$pathname." exists");
		else $this->SendMSG("Remote file ".$pathname." does not exist");
		return $exists;
	}