iOS remove all Activity Indicators

i have a Problem with my Activity Indicators. I have an Button which reload a Website and Display between a Activity Indicator. The Problem is if the User hits more than 1 Times on the Button it will rebuild a new Indicator and this Indicator freezes on the Screen all the Time. Button disabling is not working. Has anyone a Solution for this Problem. Please help.

Here is my Code:

-(IBAction) buttonReload {
Reachability *r = [Reachability reachabilityWithHostName:@"www.google.com"];
NetworkStatus internetStatus = [r currentReachabi开发者_运维技巧lityStatus];    
if ((internetStatus != ReachableViaWiFi) && (internetStatus != ReachableViaWWAN)){

    UIAlertView *myAlert = [[UIAlertView alloc]
                            initWithTitle:@"No Inet!" message:@"You need a Inet Connection..."
                            delegate:self
                            cancelButtonTitle:@"Ok"
                            otherButtonTitles:nil];
    [myAlert show];
    [myAlert release];
}

else 
{

    //Website loading
    [self performSelector: @selector(doLoadWebsite) 
               withObject: nil 
               afterDelay: 0];
    return; 
}
}

- (void) doLoadWebsite
{

//add activity indicator
NewsActivity = [[UIActivityIndicatorView alloc] initWithFrame:CGRectMake(140.0f, 180.0f, 40.0f, 40.0f)];
[NewsActivity setActivityIndicatorViewStyle:UIActivityIndicatorViewStyleGray];
[self.view addSubview: NewsActivity];
[NewsActivity startAnimating];

[NSTimer scheduledTimerWithTimeInterval:0.5 target:self selector:@selector(finishActivity) userInfo:nil repeats:YES];
//NewsActivity.backgroundColor = [UIColor grayColor];
NewsActivity.hidesWhenStopped = YES;
// Show Status Bar network indicator
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;

//perform time-consuming tasks
//load News Website
[webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.google.com"]]];
}


-(void) finishActivity {

if (!webView.loading) {
    [self.NewsActivity removeFromSuperview];
    [NewsActivity stopAnimating];

    //Hide network activity indicator
    [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
} 
else {
    [NewsActivity startAnimating];
    [UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
 }


}

You should perform stopAnimating , removeFromSuperView once the page is loaded. If the user refreshes the page again, you can again add it to the subView and startAnimating.