Hello everybody,
I know my question might seem pretty silly but I really couldn't handle it yet,here is my issue:

I am trying to modify slightly the contracts managment module, and I want to copy the value of the field 'description' of the contract to the field 'comment' of the invoice generated by the contract.
I've tried a bench of stuff (overriding some methods,creating a new method) but it's not working.
Please save my life!