Group heading of a dataGrid in c#

Hai expert...................
please help me.......
how can we give group heading of a data grid in in run time.....The following code will disply listno repeatedly...I want to avoid this repeation of list no...Please help me...
OleDbDataAdapter ad = new OleDbDataAdapter("select listno,acctno,cname,total,month1,year1 from schedule order by listno", con);
DataSet ds = new DataSet();
ad.Fill(ds, "schedule");
if (ds.Tables[0].Rows.Count > 0)
{
scheduleDataGridView.DataSource = ds;
scheduleDataGridView.DataMember = ds.Tables[0].ToString();
}