UIwebview loader on iphone

this code works fine , its show activityIndicator loading and hide after loading but lets say if its on loading stage and then i go back then my apps quit , so how to avoid this

if i go back quickly withiut site fully loaded then it quits ( i think activityIndicator is culprit)

**

- (void)webViewDidStartLoad:(UIWebView *)webView {
    [activityIndicator startAnimating];
   // myLabel.hidden = FALSE;
}
- (void)webViewDidFinishLoad:(UIWebView *)webView {
    [activityIndicator stopAnimating];
    activityIndicator.hidesWhenStopped=TRUE;
    //myLabel.hidden = TRUE;
}
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {

    self.title=@"KKH Website";

    [super viewDidLoad];
    NSURL *requestUrl = [NSURL URLWithString:@"http://www.开发者_开发百科/index.html"];
    NSURLRequest *requestObj = [NSURLRequest requestWithURL:requestUrl];
    [aWw loadRequest:requestObj];





}

** updates

if i link uiwebview delegate to fileowner then its creating isuee , but i need delegate also since i want to show loading

i forgot to release my webview :( [aWw release]; now its fixed