I create new report for my openerp payroll .Refering the default Openerp payroll report structure (report_payslip.sxw)

The details of the employee such as name , designation etc are print fine. 

Then i add the payslip computation details to the report by giving the line.   " [[repeatIn(get_payslip_lines(o.line_ids),'p') ]] "

gives the corresponding field like " 

[[ p.code ]]

[[ p.name ]]

etc... "      After sending to the server then i make a test print shows the error like this.  " Openerp Warning     name 'get_payslip_lines' is not defined

(<type 'exceptions.NameError'>, NameError("name 'get_payslip_lines' is not defined",), <traceback object at 0x064742

how can be solve this.. or   How can be define the name get_payslip_lines in openoffice...