function G(id) {
    return document.getElementById(id);
}
function song() {
    this.ID = G(arguments[0]);
    if (!this.ID) {
        alert("您要设置的\"" + arguments[0] + "\"初始化错误\r\n请检查标签ID设置是否正确!");
        this.ID = -1;
        return;
    }
    this.TimeSpan = 100;
    this.colors = new Array("red", "green", "yellow", "blue");
    if (typeof arguments[1] == "number") this.TimeSpan = arguments[1];
    if (typeof arguments[2] == "string") this.colors = arguments[2].split(",");
}
song.prototype.start = function () {
    if (this.ID == -1) return;
    var ID = this.ID;
    var colors = this.colors;
    var font = ID.innerHTML;
    var currentColor = colors[rand(colors.length) - 1];
    var pv = 1;
    var msobj = this;
    msobj.change = function () {
        var str = "<span style=\"color:" + currentColor + "\">";
        str += font.substring(0, pv) + "</span>" + font.substring(pv);
        ID.innerHTML = str;
        pv++;
        if (pv == (font.length + 1)) {
            pv = 0;
            currentColor = colors[rand(colors.length) - 1];
        }
    }
    setInterval(msobj.change, this.TimeSpan);
}
//生成随机数方法
rnd.today = new Date();
rnd.seed = rnd.today.getTime();
function rnd() {
    rnd.seed = (rnd.seed * 9301 + 49297) % 233280;
    return rnd.seed / (233280.0);
}
function rand(number) {
    return Math.ceil(rnd() * number);
}