Thanks Abhishek, but how can we configure that, where should I put there lines ?

Hi Andromida, This is a standard format which I have given you here <field name="your field" group="put all your group name which u like to give an access of this field" /> And yeah put this line in xml part of that table/model.

I don't want to cancel anything, I want just how can I have an alert about an unpaid invoice. For example: I have an invoice, its due date is today, so this invoice should be payed today by my customer. But, I have many invoices and I can't figure out which invoice

Hey as I am getting with your last msg. that your requirement is like : you have various invoice and there is a field name due date(date field) for every invoice screen as soon as due date come and the invoice which is unpaid, it should give u an alert either a group of your user my mail or nay other means. if it is right then surly you have to define a function for this, taking consideration of due date and compare with system's date and accordingly give you an alert. Or you may also use predefined module for this name account_followup module.

Thanks a lot, Abhishek. Account_followup module is what I am serching for.