Hi again all. Still taking baby steps to learn how C#/VS work. Form design project, datagridview, linked to a very simple 2-table MSAccess database. All good to that point, understand what code fills my grid with either table A or Table B. Now trying to spread my wings a little further by having the grid empty on open, use radio buttons to pick A or B, then a "launch button" to (1) set the datasource and (2) display the new data. The fill event apparently happens during the form load, but not clear how to "change my mind" after the load event and populate the grid with whatever I select at that point. I can probably write the necessary code, just not sure where to put it as it seems to me it would involve some kind of a ?reload? or ?refresh? event and I don't know of C#/VS has such a thing. Help welcome, once again. Not urgent, just learning how to code and chew gum.