ion changeTheme() {
                switch (document.getElementById("themeDino").value) {
                    case "default":
                        location.href = "index.html";
                        break;
                    case "hurdling":
                        location.href = "1_hurdling.html";
                        break;
                    case "gymnastics":
                        location.href = "2_gymnastics.html";
                        break;
                    case "surfin