check internet connection with NSURLConnection and Google in response to http://stackoverflow.com/a/13736429/613541

gistfile1.m

	dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
		NSString *urlString = @"http://www.google.com/";
		NSURL *url = [NSURL URLWithString:urlString];
		NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
		[request setHTTPMethod:@"HEAD"];
		NSHTTPURLResponse *response;
		
		[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:NULL];
		
		if ([response statusCode] == 200)
		{
			dispatch_async(dispatch_get_main_queue(), ^{
				// Do anything you would like to do as if you have Internet connection
				UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Success" message:@"Google server return HTTP Status Code 200 OK" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
				[alertView show];
			});
		}
		else
		{
			dispatch_async(dispatch_get_main_queue(), ^{
				// Do anything you would like to do as if you cannot see Google homepage
				UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Error" message:@"Connect to Google failed or Google server did not return HTTP Status Code 200" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
				[alertView show];
			});
		}
	});