How to programmatically change a value on datagrid when another column is changed?

Question

I have a program that uses a datagrid. I am able to add/update/delete records without problems. I have one field that I want to programmatically change. When a record is added or changed, I want to set the data modified field to the current date and time.

I used the Visual Studio wizard to create the datagrid.

 

Thanks for any ideas.