public DataSet ds()
{
    string newName = Server.MapPath("..//App_Data//Uploads//") + DateTime.Now.ToString("hhmmss") + ".xls";

                FileUpload1.SaveAs(newName);
                // string connStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + newName + ";Extended Properties=Excel 8.0;";
                string connStr = string.Empty;

                if (type3.Equals(".xlsx"))
                {
                    connStr = "Provider=Microsoft.Ace.OleDb.12.0;Data Source=" + newName +
                              ";Extended Properties='Excel 12.0 Xml; HDR=YES; IMEX=1'";
                }

                else if (type3.Equals(".xls"))
                {
                    connStr = "Provider=Microsoft.Jet.OleDb.4.0;" + "data source=" + newName +
                              ";Extended Properties='Excel 8.0; HDR=YES; IMEX=1'";
                }
                OleDbConnection conn = new OleDbConnection(connStr);
                if (conn.State.ToString() == "Closed")
                {
                    conn.Open();
                }
                DataTable dt = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
                var tableName = dt.Rows[0][2].ToString().Trim();
                var str1 = string.Format("Select * from [{0}]", tableName);
                OleDbDataAdapter oda = new OleDbDataAdapter(str1, conn);
                DataSet ds = new DataSet();
                oda.Fill(ds);
                conn.Close();
                File.Delete( newName );
                return ds
}