Code review comment for lp:~nicolariolini/account-invoicing/add_module_account_payment_term_month

Hi Nicola, Lorenzo, Holger,
what about delete "commercial_month" field and put this code instead?
"if line.months != 0:"

And in the view set the field "days" required if "months" if false and viceversa:

<field name="months" attrs="{'required':[('days','=',False)]}"/>

and

<xpath expr="/form/group/group/field[@name='days']" position="attributes">
    <attribute name="attrs">{'required':[('months','=',False)]}</attribute>
</xpath>