var imageURL = "http://www.law.ru.ac.th/joomla1015s/templates/meedeehost.com/images/toggle_plus.png";

            if (document.images) {
                var toggle_subtract = new Image();
                toggle_subtract.src = "http://www.law.ru.ac.th/joomla1015s/templates/meedeehost.com/images/toggle_subtract.png";

                var toggle_plus = new Image();
                toggle_plus.src = "http://www.law.ru.ac.th/joomla1015s/templates/meedeehost.com/images/toggle_plus.png";
            }

            function swapImage() {
                if (document.images) {
                    if (imageURL == "http://www.law.ru.ac.th/joomla1015s/templates/meedeehost.com/images/toggle_plus.png") imageURL = "http://www.law.ru.ac.th/joomla1015s/templates/meedeehost.com/images/toggle_subtract.png";
                    else imageURL = "http://www.law.ru.ac.th/joomla1015s/templates/meedeehost.com/images/toggle_plus.png";

                    document.swapToggle.src = imageURL;
                }
            }