how to program telerik rad grid

for (int i = 0; i < grdhd.Items.Count; i++)
                {
                    if ((grdhd.Items[i].FindControl("chkhd") as CheckBox).Checked)
                    {
                        <big>string[] appdate = grdhd.Items[i].Cells[1].Text.Split('/');</big>
                        days = Convert.ToSingle(days - 0.5);
                        objhd.EmpCode = Session["EmpCode"].ToString();
                        objhd.EmpNo = Convert.ToInt32(Session["UserID"]);
                        objhd.Day = grdhd.Items[i].Cells[2].Text;
                        objhd.hddates = Convert.ToDateTime(appdate[1].ToString() + "/" + appdate[0].ToString() + "/" + appdate[2].ToString());
                        objhd.Slot = (grdhd.Items[i].FindControl("ddlslot") as DropDownList).SelectedItem.Text;
                        if (Session["UserName"] != null)
                            objhd.CreatedBy = Session["UserName"].ToString();
                        objhd.CreatedDate = System.DateTime.Now;
                        objhd.ModifiedBy = "";
                        objhd.ModifiedDate = System.DateTime.Now;
                        objhd.DeletedFlag = '0';
                        objhd.Insert(objhd);
                    }
                }