MS Expression Blend: Sketchflow - Populating a sub datagrid with data upon selecting a specific row of a master datagrid?

I've recently started using Expression Sketchflow to prototype some user interface designs. I currently have a master datagrid at the top of the page, which I would like to allow the user when selecting a particular grid row to see a sub-datagrid below be populated with specific data relevant to that specific row of master data.

Could anyone shed some light on the subject!?

Help greatly appreciated.

I figured out how to do this by reading this article: Expression Blend 3 – secrets of working with data.

Here's the basic steps (you already did a couple it sounds like)

1. Create your sample data set
2. Under the Data tab select the List Mode and drag your collection onto the screen, a list view of your data will be created (Master datagrid)
3. Now, select the Details Mode and drag and drop your collection onto the screen where you want the details to be displayed. (sub datagrid)
4. Tweak the fields displayed by dragging properties into the respective containers or modifying the XAML / Bindings list

If you have a child collection in your data, you may have to jump through a few more hoops.