How do I know if a databound form has been updated?

[ValMac]

I have a vb.net 2010 application using databinding to a MSAccess 2000 database (Don’t ask – it’s what the client is using). The application is similar to a Customers/orders application. The “Customer” fields are databound controls on the form and the ‘orders’ are in a DataGridView. Several of the controls in both the form and the dgv are comboboxes bound to other tables from the database. The user can select new customers, edit customer details, add or delete orders and also create new customers. Some updates also occur behind the scenes when field or column values are changed in response user changes.

My problems arise when the user changes the customer. I want to prompt him/her to save changes if necessary. What is the simplest way to find out if any changes have been made? It ought to be easy but after numerous hours of trying different things that don’t work I need help. I’m new to databinding and fairly new to VB.NET so forgive me if this is a really stupid question.