How to add column name in excel using C#

string connectionstring ="Server=(local);initial catalog=Test;Trusted_Connection=True";
            SqlConnection sqlConnection = new SqlConnection(connectionstring);
            SqlCommand cmd = new SqlCommand();
            SqlDataReader reader;
            DataSet ds = new DataSet();
            cmd.CommandText ="select * from Empdetails"
            cmd.CommandText += " where shifttype  = @par "
            cmd.Parameters.Add("@par", SqlDbType.Int).Value = j;
            cmd.CommandType = CommandType.Text;
            cmd.Connection = sqlConnection;
            sqlConnection.Open();
            reader = cmd.ExecuteReader();
            if (reader.HasRows)
            {
                System.IO.StreamWriter sw_In = new System.IO.StreamWriter("C:\Users\God\Desktop\DataDump\" + j + "Excel.xls");
                while (reader.Read())
                {
                    for (int i = 0; i< reader.FieldCount; i++)
                    {
                        sw_In.AutoFlush = true;
                        sw_In.Write(reader[i].ToString() +"\t");
                    }
                        sw_In.Write("\n");
                }

            }
            sqlConnection.Close();
            reader.Close();

1    Suresh    9867689098    IN   Chennai
2    Rajesh    9840512112    IN   Chennai
3    Vikash    9844521213    IN   Chennai
4    Ramesh    9955454213    IN   Chennai
5    Kumar     9840521210    IN   Chennai

select * from Empdetails

ID    Name       Mobile      Shift    Place
1    Suresh    9867689098    IN     Chennai
2    Rajesh    9840512112    IN     Chennai
3    Vikash    9844521213    IN     Chennai
4    Ramesh    9955454213    IN     Chennai
5    Kumar     9840521210    IN     Chennai