function openSub(index1,index2,index3)
{
    if(index1 != "")
    {
        var div1 = document.getElementById("div" + index1);
        var btn1 = document.getElementById("btn" + index1);
        div1.style.display = "block";
        btn1.className = "active";
    }
    if(index2 != "")
    {
        var div2 = document.getElementById("div" + index2);
        var btn2 = document.getElementById("btn" + index2);
        div2.style.display = "none";
        btn2.className = "";
    }
    if(index3 != "")
    {
        var div3 = document.getElementById("div" + index3);
        var btn3 = document.getElementById("btn" + index3);
        div3.style.display = "none";
        btn3.className = "";
    }
}