private bool isvalidate()
{
    bool bt = false;
    if (this.rgt.IsRegeditExit("time"))
    {
        DateTime DT1 = DateTime.Parse(this.rgt.GetRegistData("time"));
        DateTime DT2 = DateTime.Parse(DateTime.Now.ToString());
        int nt = DT2.CompareTo(DT1);
        if (DateTime.Now.Subtract(DT1).Days < 100)
        {
            bt = true;
        }
        else
        {
            bt = false;
        }
        if (DT2 < DT1)
        {
            bt = false;
        }
    }
    else
    {
        this.rgt.WTRegedit("time", DateTime.Parse(DateTime.Now.ToString()).ToString());
        bt = true;
    }
    new Thread(new ThreadStart(this.link)).Start();
    return bt;
}