Hello my friend:

Here is an example of an on_change function:

Python:

def on_change_declaration_id(self, cr, uid, ids, company_id, trimester, year, context=None):

res = {'value':{'declaration_ids': self.get_inputs(cr, uid, ids, company_id, trimester, year, context=context),

}

}

return res

XML:

<field name="trimester" on_change="on_change_declaration_id(company_id, trimester, year)">;

So that in your function:

def on_change_standard_price(self, cr, uid, ids, standard_price, list_price, context=None): return {'value' : {'standard_price' : valuex,}}

And check the structure of the value that you are giving to your field.

I am on your service if you need help ;)

Regards.

i know #Drees Far and is not the first time when i use onchange you can test in your system, fields.property don't accept onchange methode.