Add Column In invoice

hello…
I m new in dolibarr…
please help me
My requirement is…
i want to show one extra column in invoice pdf called Lenght/Breadth (this column ) along with vat,u.p.net, qty ,and total…
please tell me how to do it…

pdf documens are generated by programs, so adding a column will need a developpement.
If you are not a developper, you can try building an odt template and use it in place of pdf.

on Dolibarr wiki you find the method for document developpements
http://wiki.dolibarr.org/index.php/Create_a_PDF_document_template
http://wiki.dolibarr.org/index.php/Create_an_ODT_document_template