ios - How to add a right bar button to a navigation bar in iphone -

i want add right bar button item navigation bar, on click, performs function.

i have created following code add right bar button item, after done, bar button item not getting displayed in navigation bar:

-(void)viewdidload{     self.navigationitem.rightbarbuttonitem =      [[[uibarbuttonitem alloc]             initwithbarbuttonsystemitem:uibarbuttonsystemitemadd                                                                                                                                      target:self                                 action:@selector(add:)] autorelease];     }  -(ibaction)add:(id)sender {     taddnewjourney *j=[[taddnewjourney alloc]init];     [app.navigationcontroller pushviewcontroller:j animated:yes];     [j release]; } 

-(void)viewdidload {      [super viewdidload];     app.navigationcontroller.navigationitem.rightbarbuttonitem = [[[uibarbuttonitem alloc] initwithbarbuttonsystemitem:uibarbuttonsystemitemadd target:self action:@selector(add:)] autorelease]; }  -(ibaction)add:(id)sender {     taddnewjourney *j=[[taddnewjourney alloc]init];     [app.navigationcontroller pushviewcontroller:j animated:yes];     [j release]; } 

try other answers. posted answer work if viewcontroller not have navigation controller think problem.