function openURL(url) {
    switch (url) {
        case 'product':
            window.location = "Products.htm";
            break;
        case 'contact':
            window.location = "ContactUs.htm";
            break;
        case 'talk':
            window.location = "ScientificTalk.htm";
            break;
        case 'about':
            window.location = "AboutUs.htm";
            break;
        default:
            break;
    }
}