error in printing form in woocommerce

I am creating a payment gateway plugin for woocommerce form my payment gateway.
After i click on the checkout page through my payment gateway. I am getting an syntax error.I think i am not wrong below is my process_payment function code

         /**
         * Process the payment and return the result
         **/
        function process_payment($order_id){
            global $woocommerce;
            $order = new WC_Order($order_id);
            $order_id = $order_id;
            $the_order_total = $order->order_total;
            $mercahntId=$this->merchant_id;
            $merchantPassword=$this ->merchant_password;
            $retrunUrl=$this->notify_url;
            $paymentGatewayUrl=$this ->liveurl;

            echo '<form name="Generator" method="post" action="' . $paymentGatewayUrl . '">';
            echo '<input type="hidden" name="UID" value="' . $mercahntId . '">';
            echo '<input type="hidden" name="PWD" value="' . $merchantPassword . '">';
            echo '<input type="hidden" name="ProductDesc" value="' . $order_id . '">';
            echo '<input type="hidden" name="returnURL" value="' . $retrunUrl . '">';
            echo '<input type="hidden" name="Amount" value="' . $the_order_total . '">';
            echo'</form>';
            die();

            //return array('result' => 'success', 'redirect' => $order->get_checkout_payment_url( true ));
        }

its give me an error SyntaxError: Unexpected token <

I think i am using the correct syntax for printing form in woocommerce.Any idea?

One more question how can i enable to find out the error on which page and line no. in woocommerce.