Check Boxes / Radio Buttons

I have a sheet that the user can select a single part number using a Radio Button. This works fine but I would like to use Check boxes for a couple of reasons:

1. I Like them better visually
2. Click once to select, click again to de-select

Is there any way to make check box's behave similar to a radio button in that only one can be selected at a time (it is OK to have nothing selected as well)

I know that I can do this with code, but I am runnig about 20 boxes and the code gets to be a pain just to deselect the other boxes. Can you set up an "array" of controls similar to how it can be done using .NET programming so that all of the boxes could be looped through rather than addressing each one by a unique name? (have all controls point to a single subroutine)

Thanks for any insights or suggestions

Lee

These check boxes are placed directly on a sheet, not a form. Can I group them on a shhet as well?