NAME
        LockAmigaGuideBase - Lock an AmigaGuide client.         (V34)
    SYNOPSIS
        key = LockAmigaGuideBase (AMIGAGUIDECONTEXT handle);
        d0                                            a0
        LONG LockAmigaGuideBase (AMIGAGUIDECONTEXT);
    FUNCTION
        This function is used to lock the AmigaGuide context handle
        while working with data obtained with the the
        GetAmigaGuideAttr() function.
    INPUTS
        handle - AMIGAGUIDECONTEXT handle obtained with
            OpenAmigaGuideAsync().
    RETURNS
        Returns a key to pass to UnlockAmigaGuideBase().
    SEE ALSO
        UnlockAmigaGuideBase()