Lost as to how I can get the web grids to raise navigated events to get other 2 grids to synch.

I have a simple web app that will display 3 grids.
The 1st is bound to a Log MM.NET BO
The 2nd is bound to a Document MM.NET BO (which is reg on web form as child of Log BO)
The 3rd is bound to a DocumentItem MM.NET BO (which is reg on web form as child of Document BO)

So I want to select a Log in the first grid and have the other grids auto synch.
The Document grid would get documents corresponding to the selected Log in Log grid (via Log BO)
The DocumentItem grid would get document items corresponding to the selected Document in Document grid (via Document BO)

In my Document and DocumentItems BOs I have coded the Protected Overrides Sub HookParentRetrieved and Protected Overrides Sub HookParentNavigated to call Me.GetDocuments(CInt(e.PrimaryKeyValue))and Me.GetDocumentItems(CInt(e.PrimaryKeyValue)).

ANY HELP IS MOST APPRECIATED!!!