I'm modifying the layout of an invoice and quotation. I want it to show the item number in the quotation, example:

No.  |  Description       | Tax  |  Quantity  |  Unit Price    | Price    |

1     | Car                     | 4%  |  1.00         | $10.00          | $10.00 |

2     | Bus                     | 4%  |  1.00         | $10.00          | $10.00 |

3     | Laptop                | 4%  |  1.00         | $10.00          | $10.00 |

What tag should I use to create that 1,2,3 Item squence in the No. Column?

I'm using the OpenERP Report Designer with OpenOffice to create the reports.

Thanks!