<oRadioGroup>: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 group.


        Applicable Hit Test Return Values
        ---------------------------------------------------------------------
        Value   Constant       Description
        ---------------------------------------------------------------------
        > 0     Not Applicable The position in the radio group of the radio
                               button whose region the mouse is within
        0       HTNOWHERE      The mouse cursor is not within the region of
                               the screen that the radio group occupies
        -1      HTTOPLEFT      The mouse cursor is on the radio group's
                               border
        -2      HTTOP          The mouse cursor is on the radio group's top
                               border
        -3      HTTOPRIGHT     The mouse cursor is on the top right corner of
                               the radio group's border
        -4      HTRIGHT        The mouse cursor is on the radio group's right
                               border
        -5      HTBOTTOMRIGHT  The mouse cursor is on the bottom right corner
                               of the radio group's border
        -6      HTBOTTOM       The mouse cursor is on the radio group's bottom
                               border
        -7      HTBOTTOMLEFT   The mouse cursor is on the bottom left corner
                               of the radio group's border
        -8      HTLEFT         The mouse cursor is on the radio group's left
                               border
        -2049   HTCLIENT       The mouse cursor is within the radio group's
                               screen region but not on a radio button
        ---------------------------------------------------------------------

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

        hitTest() is a method of the RadioGroup class that is used for
        determining if the mouse cursor is within the region of the screen
        that any of the RadioButto objects contained within the radio group
        occupies.  hitTest() accomplishes this by calling the hitTest()
        method of each of the radio buttons in its group.