iOS: How to identify a tel: link has been clicked in a UIWebView

I wanted to ask the user whether they are SURE that they want to initiate a phone call to a tel: link clicked on inside a UIWebView.

Here's how:
1. in the UIWebViewDelegate, implement this method:

- (BOOL) webView:(UIWebView *)_webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {  

2. inside this function check this runtime condition:

if ([request.URL.scheme isEqualToString:@"tel"]) 

3. respond to this "event" as you like (I created a yes/no dialog for making sure the user wants to call the number).