Kid 0 - XuiRadioBox
"Selection" callback on Enter KeyDown
"Selection" callback on MouseDown
v0 : $$FALSE = not selected
$$TRUE = selected
XuiRadioBox grids display a text string next to a small circle that is either selected or not selected.
Selecting a XuiRadioBox grid first deselects all other XuiRadioBox grids in the same window and group, then selects itself. Therefore no more than one XuiRadioBox grid in a group is ever selected.
XuiRadioBox grids generate a Selection callback message with v0=$$FALSE when deselected and v0=$$TRUE when selected.
A window with a single XuiRadioBox is not particularly useful, since once selected, the only ay the user can deselect it is by selecting another XuiRadioBox grid in the window, none of which exist.
