Restrict users from modifying other's sales files

We have this problem that any user can modify others sales file created.

Sample scenario:

User1: created this sales quote file in Navision and reserve a last; product for a customer.

User2: he intentionally unreserve this one product from User1 to offer to his other customer.

Can anyone suggest what to changein user roles? Thanks.

You can use security filters if you are running SQL maybe. I would turn on the Change Log, though, and tell your salespeople that you’re tracking it and that there will be consequences for people who do it.

You can use approval system.

Thanks guys. I’ll try that.