<oRadioButto>:hitTest(<nMouseRow>, <nMouseCol>)
        --> <nHitStatus>

        <nMouseRow> is a numeric value that indicates the current screen row
        position of the mouse cursor.

        <nMouseCol> is a numeric value that indicates the current screen
        column position of the mouse cursor.

        Returns a numeric value that indicates the relationship of the mouse
        cursor with the radio button.

        Applicable Hit Test Return Values
        ---------------------------------------------------------------------
        Value   Constant    Description
        ---------------------------------------------------------------------
        0       HTNOWHERE   The mouse cursor is not within the region of the
                            screen that the radio button occupies
        -1025   HTCAPTION   The mouse cursor is on the radio button's caption
        -2049   HTCLIENT    The mouse cursor is on the radio button
        ---------------------------------------------------------------------

        Button.ch contains manifest constants for the RadioButto:hitTest()
        return value.

        hitTest() is a method of the RadioButto class that is used for
        determining if the mouse cursor is within the region of the screen
        that the radio button occupies.

        hitTest() returns a numeric value in order to maintain an appropriate
        level of symmetry with the hitTest() methods contained within the
        other data input control classes.