How to reset UIWebView's zoom

uiwebview_zoom.m

  UIScrollView *sv = nil;

  // if iOS5 the scrollView property exists!
  if ([self.webView respondsToSelector:@selector(scrollView)]) 
    sv = webView.scrollView;
  else 
    sv = [webView.subviews objectAtIndex:0];
  
  
  CGSize  theSize = [sv contentSize];
  CGRect  theFrame = [sv frame];
  CGFloat zoomScale = theFrame.size.width / theSize.width;
  
  [sv setContentOffset:CGPointZero animated: YES];
  [sv setZoomScale:(zoomScale) animated:YES];