Update index.md

Author: zamronypj

utilities/identifying-client-user-agent/index.md

@@ -47,6 +47,10 @@ auserAgent := container['ua'] as IUserAgent;
 
 Before you can identify client user-agent, you need to set user-agent string to instance of `IUserAgent`. User-agent of each request can be read from `IRequest` instance.
 
+```
+auserAgent.userAgent := request.headers().getHeader('User-Agent');
+```
+or
 ```
 auserAgent.userAgent := request.env.httpUserAgent();
 ```