if (recentSearches != null) {
// set null before uninstalling. otherwise the popup menu is not
// allowed to be changed.
RecentSearches rs = recentSearches;
recentSearches = null;
rs.uninstall(this);
}
if (isValidRecentSearchesKey(recentSearchesSaveKey)) {
recentSearches = new RecentSearches(recentSearchesSaveKey);
recentSearches.install(this);