How can I display master/details in the same datagrid?

Hi, I want to display my data in a master/detail datagrid.(nested datagrid?) like data displayed in Access. That is, there''s a "+" in the head of each master row, and if click on the "+", the detail grid will show up, just in the same grid, not in a separate grid. I know I could add a datarelation and set the datasource of the datagrid as dataset, but the way this displays data is not what I want. I don''t want to see datarelation names in datagrid, I just want to click the "+" and see the detail data. How can I do this? Thanks.