I added a toolBar with this code:
- (void)viewWillAppear:(BOOL)animated {
    UIBarButtonItem *yesterday = [[UIBarButtonItem alloc]initWithTitle:@"Yesterday" 
                                                                 style:UIBarButtonItemStyleBordered target:self action:@selector(yesterday:)];
    UIBarButtonItem *today = [[UIBarButtonItem alloc]initWithTitle:@"Today" 
                                                             style:UIBarButtonItemStyleDone target:self action:@selector(today:)];
    UIBarButtonItem *tomorrow = [[UIBarButtonItem alloc]initWithTitle:@"Tomorrow" 
                                                                style:UIBarButtonItemStyleBordered target:self action:@selector(tomorrow:)];
    UIBarButtonItem *month = [[UIBarButtonItem alloc]initWithTitle:@"Month" 
                                                             style:UIBarButtonItemStyleBordered target:self action:@selector(month:)];
    NSArray *items = [NSArray arrayWithObjects:yesterday,today,tomorrow,month, nil];
    [yesterday release];
    [today release];
    [tomorrow release];
    [month release];
    UIToolbar *toolbar = [[UIToolbar alloc] init];
    [toolbar sizeToFit];
    [toolbar setFrame:CGRectMake( 0, 20, 320, 40)];
    [toolbar setItems:items];
    [self.navigationController.view addSubview:toolbar];
}
but when i change the view using the navigation controller the toolbar stays there...
how can i remove that subview?