removing repeated code

 private void PopulateYear()
        {
            DDYEAR.Items.Clear();
            ListItem lt = new ListItem();
            lt.Text = "YYYY";
            lt.Value = "0";
            DDYEAR.Items.Add(lt);
            for (int i = DateTime.Now.Year; i >= 1910; i--)
            {
                lt = new ListItem();
                lt.Text = i.ToString();
                lt.Value = i.ToString();
                DDYEAR.Items.Add(lt);
            }
            DDYEAR.Items.FindByValue(DateTime.Now.Year.ToString()).Selected = true;
        }

 public DataTable GetDatacom()
        {
            conn.Open();
            sqlstr = " Select * from  COMPANY";
            SqlDataAdapter da = new SqlDataAdapter(sqlstr, conn);
            DataSet ds = new DataSet();
            da.Fill(ds, "C_DETAILS");
            da.Dispose();
            ds.Dispose();
            conn.Close();
            return ds.Tables[0];
        }

i have the following code repeated in many pages  in some cases only the sql query chnages

instead of repeating all code lines in each and everypage

how can i use the same from class file