('minimum_balance',models.DecimalField(decimal_places=2,default=0,help_text='The minimal amount of money allowed for the balance at the end of a payment. You can specify negative amount.',max_digits=5,verbose_name='Minimum balance')),
('maximum_balance',models.DecimalField(decimal_places=2,default=50,help_text='The maximal amount of money allowed for the balance.',max_digits=5,verbose_name='Maximum balance')),
('maximum_balance',models.DecimalField(decimal_places=2,default=50,help_text='The maximal amount of money allowed for the balance.',max_digits=5,verbose_name='Maximum balance',null=True,blank=True)),