NSMutableDictionary *dict = [[NSMutableDictionary alloc] init];  
    if(oldView != nil){
        [dict setObject:oldView forKey:@"oldView"]; 
    }
    if(newView != nil){
        [dict setObject:newView forKey:@"newView"]; 
    } 
    [NSTimer scheduledTimerWithTimeInterval:0.0 target:self selector:@selector(onTimer:) userInfo:dict repeats:NO];  
    [dict release];

 
- (void)onTimer:(NSTimer *)timer {  
    UIView *oldView = [[timer userInfo] objectForKey:@"oldView"];
    UIView *newView = [[timer userInfo] objectForKey:@"newView"];  
    [UIView animateWithDuration:2.0  delay:0
                        options:UIViewAnimationOptionAllowUserInteraction
                     animations:^{  
                         oldView.alpha = 0.0
                         newView.alpha = 1.0;  
                     }