(iOS) UIAlert View Example - Has a delegate for Yes/No Taps Will only display popup once

alert.m

- (void) showConfirmationAlert 
{
    // A quick and dirty popup, displayed only once
    if (![[NSUserDefaults standardUserDefaults] objectForKey:@"HasSeenPopup"]) 
    {
        UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"Question"  
                                                       message:@"Do you like cats?" 
                                                      delegate:self 
                                             cancelButtonTitle:@"No" 
                                             otherButtonTitles:@"Yes",nil];
	[alert show];
	[alert release];
        [[NSUserDefaults standardUserDefaults] setValue:@"YES" forKey:@"HasSeenPopup"];
    }	
}    


- (void) alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex 
{	
	// 0 = Tapped yes
	if (buttonIndex == 0)
	{
		// ....
	}
}

Yes is actually buttonIndex of 1

Should replace this by UIAlertController now~