void loadChartUser()
{
double total = Convert.ToDouble(thongKe.GetTongSo("SELECT COUNT(*) FROM dbo.THETHUVIEN"));
double totalMale = Convert.ToDouble(thongKe.GetTongSo("SELECT COUNT(*) FROM dbo.THETHUVIEN WHERE Gioitinh=N'Nam'"));
double totalFeMale = Convert.ToDouble(thongKe.GetTongSo("SELECT COUNT(*) FROM dbo.THETHUVIEN WHERE Gioitinh=N'Nữ'"));
double maleStudentsPercentage = (totalMale * (100 / total));
double fmaleStudentsPercentage = (totalFeMale * (100 / total));
crtUser.Titles.Add("Tổng Số User - " + total + " - 100 %" + "(" + "Đơn Vị %" + ")");
crtUser.Series["s1"].IsValueShownAsLabel = true;
crtUser.Series["s1"].Points.AddXY("Nam", maleStudentsPercentage.ToString("0.00"));
crtUser.Series["s1"].Points.AddXY("Nữ", fmaleStudentsPercentage.ToString("0.00"));
}