private void btnPreview_Click(object sender, EventArgs e)
{
Report.BangDiem obj = new Report.BangDiem();
string maLop = lop.Select(string.Format("tenlop ='{0}'", comboBox1.Text.Trim()))[0][0].ToString();
string maMH = monHoc.Select(string.Format("[Tên môn học] ='{0}'", comboBox2.Text.Trim()))[0][0].ToString();
int lan = Convert.ToInt32(comboBox3.Text);
string[] name = { "@mamh", "@malop", "@lan" };
object[] param = { maMH, maLop, lan };
DataTable bangDiem = DBAccess.ExecuteQuery("SP_LayBangDiem", name, param, 3);
obj.SetDataSource(bangDiem);
obj.SetParameterValue("@malop", maLop);
obj.SetParameterValue("@mamh", maMH);
obj.SetParameterValue("@lan", lan);
obj.SetParameterValue("tengv", DBAccess.hoTen);
crptView.ReportSource = obj;
}