public DataTable SelectAll(string FilePath, string Extension, string isHDR)
        {

            string conStr = "";

            switch (Extension)
            {

                case ".xls": //Excel 97-03

                    conStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0}; Extended Properties='Excel 8.0;HDR={1}'";

                    break;

                case ".xlsx": //Excel 07

                    conStr = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties='Excel 8.0;HDR={1}'";

                    break;

            }

            conStr = String.Format(conStr, FilePath, isHDR);

            OleDbConnection connExcel = new OleDbConnection(conStr);

            OleDbCommand cmdExcel = new OleDbCommand();

            OleDbDataAdapter oda = new OleDbDataAdapter();

            DataTable dt = new DataTable();

            cmdExcel.Connection = connExcel;



            //Get the name of First Sheet

            connExcel.Open();

            DataTable dtExcelSchema;

            dtExcelSchema = connExcel.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);

            string SheetName = dtExcelSchema.Rows[0]["TABLE_NAME"].ToString();

            connExcel.Close();



            //Read Data from First Sheet

            connExcel.Open();

            cmdExcel.CommandText = "SELECT * From [" + SheetName + "]";

            oda.SelectCommand = cmdExcel;

            oda.Fill(dt);

            connExcel.Close();



            return dt;



        }