customize the text of navigationbar

UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 320, 30)];
label.font = [UIFont boldSystemFontOfSize:14.0];
label.shadowColor = [UIColor colorWithWhite:0.0 alpha:0.5];
label.backgroundColor = [UIColor clearColor];
label.textAlignment = UITextAlignmentCenter;
label.textColor = [UIColor whiteColor];
self.navigationItem.titleView = label;
label.text = [dataItem objectForKey:@"title"];
[label release];