Error while generating report on ODOO 10

I got the following error when I click the PRINT EXCEL REPORT button: File “/odoo/custom/addons/purchase_order_xlsx/wizard/purchase_xls.py”, line 144, in action_purchase_report workbook.save(filename) File “/usr/lib/python2.7/dist-packages/xlwt/Workbook.py”, line 662, in save doc.save(filename, self.get_biff_data()) File “/usr/lib/python2.7/dist-packages/xlwt/CompoundDoc.py”, line 261, in save f = open(file_name_or_filelike_obj, ‘w+b’) IOError: [Errno 13] Permission denied: ‘Purchase Report.xls’

Moved to the bahmni category.