void InvertListBrowser(Object *wnd, Object *lb) {
    struct Window *window;
    struct List *list;
    struct Node *node;
    uint32 selected;
 
    // get list
    IIntuition->GetAttr(LISTBROWSER_Labels, lb, (uint32 *)&list);
 
    // remove list
    IIntuition->SetAttrs(lb, LISTBROWSER_Labels, ~0, TAG_END);
 
    // make changes
    for (node = list->lh_Head; node->ln_Succ; node = node->ln_Succ) {
        selected = FALSE;
        IListBrowser->GetListBrowserNodeAttrs(node,
            LBNA_Selected, &selected,
            TAG_END);
        IListBrowser->SetListBrowserNodeAttrs(node,
            LBNA_Selected, !selected,
            TAG_END);
    }
 
    // get intuition window pointer
    window = NULL;
    IIntuition->GetAttr(WINDOW_Window, wnd, (uint32)&window);
 
    // readd list and refresh
    IIntuition->SetGadgetAttrs((struct Gadget *)lb, window, NULL,
        LISTBROWSER_Labels, list,
        TAG_END);
}