_columns = {
'name': fields.char('Description', size=64, select=True, readonly=True, states={'draft':[('readonly',False)]}),
'origin': fields.char('Source Document', size=64, help="Reference of the document that produced this invoice.", readonly=True, states={'draft':[('readonly',False)]}),
+ 'supplier_invoice_number': fields.char('Supplier Invoice Number', size=64, help="The reference of this invoice as provided by the supplier.", readonly=True, states={'draft':[('readonly',False)]}),
'type': fields.selection([
('out_invoice','Customer Invoice'),
('in_invoice','Supplier Invoice'),