How to implement a Modal View in a TabBar iOS app

I am trying to present a modal view in a tabbar app. I am using the code

- (IBAction)newView
{
开发者_StackOverflow [self.viewController presentModalViewController:viewController 
                                        animated:YES];
}

linked to a button. When the button is pressed, nothing happens and nothing is displayed on the log. This is most likely simple to fix, but I have not found anything that has worked yet.

Thanks

Use this and you rock:

[self presentModalViewController:viewController animated:YES];