: radio_button {
action alignment fixed_height fixed_width 
height is_enabled is_tab_stop key label 
mnemonic value width
}
A radio button is one of a group of buttons composing a radio column or radio row. These work like the buttons on a car radio: only one can be selected at a time, and when one is pressed, any other button in the column (or row) that is on is turned off. An optional label appears to the right of the radio button. The PDB feature reports an error if you attempt to place a radio button outside a radio column or radio row.
The text displayed to the right of the radio button.
A quoted string (no default). If the value is "1", the radio_button is on; if it is "0", the radio_button is off; all other values are equivalent to "0".
If by some chance more than one radio_button in a radio cluster has value = "1", only the last one is turned on. (This can happen in a DCL file. Once the dialog box starts, the PDB feature manages radio buttons and ensures that only one per cluster is turned on at a time.)