How to make payment gate way?

[eluser]barryskidmore[/eluser]

Code:

function transact($cart_id = 0) {
        $this->x_array                = array(
            "x_login"                    => $this->x_login,
            "x_version"                    => $this->x_version,
            "x_delim_char"                => $this->x_delim_char,
            "x_delim_data"                => $this->x_delim_data,
            "x_url"                        => $this->x_url,
            "x_type"                    => $this->x_type,
            "x_method"                    => $this->x_method,
             "x_tran_key"                => $this->x_tran_key,
             "x_relay_response"            => $this->x_relay_response,
            "x_card_num"                => $this->x_card_num,
            "x_exp_date"                => $this->x_exp_date,
            "x_card_code"                => $this->x_card_code,
            "x_description"                => $this->x_description,
            "x_amount"                    => number_format($this->x_amount,2,'.',','),
            "x_first_name"                => $this->x_first_name,
            "x_last_name"                => $this->x_last_name,
            "x_company"                    => $this->x_company,
            "x_address"                    => $this->x_address,
            "x_city"                    => $this->x_city,
            "x_state"                    => $this->x_state,
            "x_zip"                        => $this->x_zip,
            "x_country"                    => $this->x_country,
            "x_phone"                    => $this->x_phone,
            "x_fax"                        => $this->x_fax,
            "x_email"                    => $this->x_email,
            "x_email_customer"            => $this->x_email_customer,
            "x_header_email_receipt"    => $this->x_header_email_receipt,
            "x_footer_email_receipt"    => $this->x_footer_email_receipt,
            "x_test_request"            => $this->x_test_request,
            "x_version"                    => $this->x_version,
            "x_recurring_billing"        => $this->x_recurring_billing,
            "x_duplicate_window"        => $this->x_duplicate_window,
            "x_invoice_num"                => $this->x_invoice_num,
            "x_description"                => $this->x_description,
            "x_cust_id"                    => $this->x_cust_id,
            "x_customer_ip"                => $this->x_customer_ip);
        foreach($this->x_array as $key => $value) {
            $this->x_request .= $key."=".urlencode($value).'&';
        }
        $this->x_request .= $this->x_line_item;
        $this->x_transaction = curl_init($this->x_url);
        curl_setopt($this->x_transaction, CURLOPT_HEADER,0);
        curl_setopt($this->x_transaction, CURLOPT_RETURNTRANSFER,1);
        curl_setopt($this->x_transaction, CURLOPT_POSTFIELDS,rtrim($this->x_request,'& '));
        ### curl_setopt($this->x_transaction, CURLOPT_SSL_VERIFYPEER, FALSE); // uncomment this line if you get no gateway response. ###
        $this->x_response = curl_exec($this->x_transaction);
        curl_close ($this->x_transaction);
        return $this->x_response;
    }