";
        // print_r($this->fields);
        // die();
        foreach ($this->fields as $name => $value)
            $str .= form_hidden($name, $value) . "\n";
        $str .= '
' . $this->submit_btn . '
';
        $str .= form_close() . "\n";

        return $str;
    }

    function validate_ipn()
    {
        // parse the paypal URL
        $url_parsed = parse_url($this->paypal_url);

        // generate the post string from the _POST vars aswell as load the
        // _POST vars into an arry so we can play with them from the calling
        // script.
        $post_string = '';
        if ($this->CI->input->post()) {
            foreach ($this->CI->input->post() as $field => $value) {
                $this->ipn_data[$field] = $value;
                $post_string .= $field . '=' . urlencode(stripslashes($value)) . '&';
            }
        }

        $post_string .= "cmd=_notify-validate"; // append ipn command

        // open the connection to paypal
        $fp = fsockopen($url_parsed['host'], "80", $err_num, $err_str, 30);
        if (!$fp) {
            // could not open the connection.  If loggin is on, the error message
            // will be in the log.
            $this->last_error = "fsockopen error no. $errnum: $errstr";
            $this->log_ipn_results(false);
            return false;
        } else {
            // Post the data back to paypal
            fputs($fp, "POST $url_parsed[path] HTTP/1.1\r\n");
            fputs($fp, "Host: $url_parsed[host]\r\n");
            fputs($fp, "Content-type: application/x-www-form-urlencoded\r\n");
            fputs($fp, "Content-length: " . strlen($post_string) . "\r\n");
            fputs($fp, "Connection: close\r\n\r\n");
            fputs($fp, $post_string . "\r\n\r\n");

            // loop through the response from the server and append to variable
            while (!feof($fp))
                $this->ipn_response .= fgets($fp, 1024);

            fclose($fp); // close connection
        }

        if (preg_match("/VERIFIED/", $this->ipn_response)) {
            // Valid IPN transaction.
            $this->log_ipn_results(true);
            return true;
        } else {
            // Invalid IPN transaction.  Check the log for details.
            $this->last_error = 'IPN Validation Failed.';
            $this->log_ipn_results(false);
            return false;
        }
    }

    function log_ipn_results($success)
    {
        if (!$this->ipn_log) return;  // is logging turned off?
        // Timestamp
        $text = '[' . date('m/d/Y g:i A') . '] - ';

        // Success or failure being logged?
        if ($success) $text .= "SUCCESS!\n";
        else $text .= 'FAIL: ' . $this->last_error . "\n";

        // Log the POST variables
        $text .= "IPN POST Vars from Paypal:\n";
        foreach ($this->ipn_data as $key => $value)
            $text .= "$key=$value, ";

        // Log the response from the paypal server
        $text .= "\nIPN Response from Paypal Server:\n " . $this->ipn_response;

        // Write to log
        $fp = fopen($this->ipn_log_file, 'a');
        fwrite($fp, $text . "\n\n");

        fclose($fp);  // close file
    }


    function dump()
    {
        // Used for debugging, this function will output all the field/value pairs
        // that are currently defined in the instance of the class using the
        // add_field() function.

        ksort($this->fields);
        echo '
ppal->dump() Output:
' . "\n";
        echo '' . "\n";
        foreach ($this->fields as $key => $value) echo '' . $key . ':    ' . urldecode($value) . '
';
        echo "\n";
    }


    function curlPost($paypalurl, $paypalreturnarr)
    {

        $req = 'cmd=_notify-validate';
        foreach ($paypalreturnarr as $key => $value) {
            $value = urlencode(stripslashes($value));
            $req .= "&$key=$value";
        }

        $ipnsiteurl = $paypalurl;
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $ipnsiteurl);
        curl_setopt($ch, CURLOPT_HEADER, false);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $req);
        $result = curl_exec($ch);
        curl_close($ch);

        return $result;
    }
}