if (screen.width <= 640) {
document.location = "index_600.html";
}
else if (screen.width <= 800) {
document.location = "index_800.html";
}
else if (screen.width <= 1024) {
document.location = "index_1024.html";
}
else if (screen.width <= 1152) {
document.location = "index_1152.html";
}
else if (screen.width <= 1280) {
document.location = "index_1280.html";
}
if (screen.width > 1280) {
document.location = "index_1280+.html";
}