[Mess4me]

AlphaKeloid,
а если так добавить

$(function() {
            $('select').on('change', function () {
                var selector = 'input[data-img*="' + $(this).find("option:selected").attr('name') + '"]';
                var image = $(this).parent().find(selector).attr('data-img');
                $(this).parent().find('img.over_ch').attr('src', image);
            });
            function visibilityLayer(id) {
                var e = document.getElementById(id);
                if (e.style.display == 'none')
                    e.style.display = 'block';
                else
                    e.style.display = 'none';
            }

            function changeImage(form, pic1) {
                selection = form.imagename.options[form.imagename.selectedIndex].title;
                document.images[pic1].src = selection;
            }

            function changeImage(form, pic2) {
                selection = form.imagename.options[form.imagename.selectedIndex].title;
                document.images[pic2].src = selection;
            }

            function changeImage(form, pic3) {
                selection = form.imagename.options[form.imagename.selectedIndex].title;
                document.images[pic3].src = selection;
            }


        });