Column does not belong to table Table

Hi Friends
Please help me
try
                {
                    objdata.Pslid = txtPslid.Text.ToString();
                    DataSet ds = new DataSet();
                    ds = objBL.FetchResourceEMP(objdata);
                     DataTable dt = ds.Tables[0];
                    if (dt.Rows.Count > 0)
             & ...