window.onload = function() {
    var odiv = document.getelementbyid("tab");
    var oli = odiv.getelementsbytagname("div")[0].getelementsbytagname("li");
    var acon = odiv.getelementsbytagname("div")[1].getelementsbytagname("div");
    var timer = null;
    for (var i = 0; i < oli.length; i++) {
        oli[i].index = i;
        oli[i].onclick = function() {
            show(this.index);
        }
    }
    function show(a) {
        index = a;
        var alpha = 0;
        for (var j = 0; j < oli.length; j++) {
            oli[j].classname = "";
            acon[j].classname = "";
            acon[j].style.opacity = 0;
            acon[j].style.display = "none";
            acon[j].style.filter = "alpha(opacity=0)";
        }
        oli[index].classname = "cur";
		oli[1-index].classname = "cur1";
        clearinterval(timer);
        timer = setinterval(function() {
            alpha += 2;
            alpha > 100 && (alpha = 100);
            acon[index].style.opacity = alpha / 100;
            acon[index].style.display = "block";
            acon[index].style.filter = "alpha(opacity=" + alpha + ")";
            alpha == 100 && clearinterval(timer);
        },
        5)
    }
}