M,
I have done this in a web application I wrote. As you probably know, the
datagrid web control does not inherently support master-detail datagrids.
What you need to do is:
1. Add a select button column to your datagrid (a simple google search
will give you simple instructions on this
2. Perhaps change the "selecteditem" style to bold or something to make
it stand out
3. Add the following to your html tag for the datagrid:
"Onselectedindexchanged = "datagrid1_SelectedIndexChanged" This will fire
an event when you hit the select button for a particular row in your
datagrid
4. Set your "DataKeyField" property on the datagrid to the table's field
value that links it to the detail datagrid (usually a primary key field i.e.
AuthorID)
5. Create a second datagrid (your detail datagrid)
6. In the datagrid1_SelectedIndexChanged Sub, set up and execute a
connection/command with a SQL statement that references the selectedindex of
the master datagrid in the WHERE clause of your SQL statement (i.e. SELECT
booktitles, ISBNNumber FROM tbl_Books WHERE AuthorID =
datagrid1.items.item(datagrid1.selecteditem.itemindex).Cells(0).Text
7. Bind your detail datagrid and refresh the page
That should get you started in the right direction.