Convert NSString->NSDate?

I need to convert my NSString in the end to an NSDate but I am having problems doing so. How would I achieve the same functionality with this code while making the end result an NSDate?

//Date and Format it
NSDate *now = [NSDate date];
NSDateFormatter* formatter = [[[NSDateFormatter alloc] init] autorelease];
[formatter setDateFormat:@"MM-dd-yyyy"];
NSString *dateString = [formatter stringFromDate:now];

Thanks!

Edit:

//Date and Format it
    NSDate *now = [NSDate date];
    NSDateFormatter* formatter = [[[NSDateFormatter alloc] init] autorelease];
    [formatter setDateFormat:@"MM-dd-yyyy"];
    NSString *dateString = [formatter stringFromDate:now];
    NSDate *enddate = [formatter dateFromString:dateString];
开发者_开发知识库    [[NSUserDefaults standardUserDefaults] setObject:enddate forKey:@"theDate"];

NSDate *date = [formatter dateFromString:dateString];