RadioGroup -- Overview
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 Class Function

 RadioGroup()    Create a new RadioGroup object
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 Exported Instance Variables

 bottom          Numeric value indicating the bottommost screen row
 buffer          Numeric value indicating the position in the radio group
 capCol          Indicates column where radio group's caption is displayed
 capRow          Indicates row where the radio group's caption is displayed
 caption         Character string describing the radio group on the screen
 cargo           User-definable variable
 coldBox         Characters to use when drawing a box around a radio group
 colorSpec       Indicates colors used by the radio group's display() method
 fBlock          Code block evaluated at each input focus change
 hasFocus        Logical value indicating the input focus
 hotBox          Specifies characters to use when drawing a radio group's box
 itemCount       Indicates total number of radio buttons in the radio group
 left            Indicates leftmost column where the radio group is displayed
 message         Character string that is the radio group's description
 right           Indicates rightmost column where radio group is displayed
 top             Indicates the topmost row where the radio group is displayed
 typeOut         Logical value indicating whether group contains any buttons
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 Exported Methods

 addItem()       Appends a new radio button to a radio group
 delItem()       Removes a radio button from a radio group
 display()       Shows its radio buttons on the screen
 getAccel()      Determines if a key press is interpreted as a user request
 getItem()       Retrieves a radio button from a radio group
 hitTest()       Indicates position of mouse cursor relative to radio group
 insItem()       Inserts a new radio button into a radio group
 killFocus()     Takes input focus away from the RadioGroup object
 nextItem()      Changes radio button from current item to the following one
 prevItem()      Changes radio button from current item to the previous one
 select()        Changes the selected radio button in a radio group
 setColor()      Sets the color attributes of all radio buttons in a group
 setFocus()      Gives input focus to the RadioGroup object
 setStyle()      Sets the style attribute of all radio buttons in a group