$key = $scriptProperties['captcha_key'];

if(empty($scriptProperties['code'])){
    $param = "_".strtoupper($method);
    
    if(isset($$param)){
        $p = $$param;
        
        $scriptProperties['code'] = (!empty($p[$key]) ? $p[$key] : "");
    }
}

public function process(){
        $key = $this->getProperty('captcha_key');

        $method = $this->getProperty('method');
        $code = $this->getProperty('code');
        
        if(empty($code)){
            $code = $this->modx->request->parameters[$method][$key];
        }
            
        $session_code = $_SESSION[$key];