UIWebView crash due to separate thread

Fixed the crash due to separate thread :

-(void)viewDidLoad{    

NSOperationQueue *operationQueue = [[NSOperationQueue alloc]init];

NSInvocationOperation *operation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(load) object:nil];

[operationQueue addOperation:operation];

[operation release];

[operationQueue release];

}

-(void)load {

    [NSThread sleepForTimeInterval:1];

    [self performSelectorOnMainThread:@selector(loadWebView) withObject:nil waitUntilDone:NO];

}

-(void)loadWebView{

    NSLog(@"Runnnnn...."); 

    

    UIWebView *webView = [[UIWebView alloc] initWithFrame:self.view.bounds];

    [webView setUserInteractionEnabled:YES];

    NSString *docsDirectory =         [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES) objectAtIndex:0];

NSString *newDirectory = [NSString stringWithFormat:@"%@/E-Bills", docsDirectory];

NSString *file = [newDirectory stringByAppendingPathComponent:@"eBill.pdf"];

    

    NSURL *targetURL = [[NSURL alloc] initFileURLWithPath:file];

    NSURLRequest *request = [NSURLRequest requestWithURL:targetURL];

    [webView loadRequest:request];

    [self.view addSubview:webView];

    

    [targetURL release];

    [webView release];

    

    

}