private void crystalReportViewer2_Load(object sender, EventArgs e)
{
cls.KetNoi();
DataSet dt = new DataSet();
dt = cls.Laybang("EXEC Hoadond");
CrystalReport3 m = new CrystalReport3();
m.SetDataSource(dt);
crystalReportViewer2.ReportSource = m;
}