function showdownload(){

        $("#buy").animate({opacity: 0}, {duration: 500, queue: "global"});
        document.getElementById("buy").style.display = "none";
        document.getElementById("dw").style.display = "block";
        $("#dw").animate({opacity: 1}, {duration: 500, queue: "global"});
};

function showbuy(){

        $("#dw").animate({opacity: 0}, {duration: 500, queue: "global"});
        document.getElementById("dw").style.display = "none";
        document.getElementById("buy").style.display = "block";
        $("#buy").animate({opacity: 1}, {duration: 500, queue: "global"});
};