Revise proxy configuration docs

doc-src/guide/node-configuring.md

@@ -238,24 +238,23 @@ AWS.config.apiVersion = '2012-05-04';
 ### Configuring a Proxy
 
 If you cannot connect to the internet directly, the SDK supports the use of
-HTTP or HTTPS proxies through the use of a third party HTTP agent like 
-[proxy-agent](https://github.com/TooTallNate/node-proxy-agent).
+HTTP or HTTPS proxies through the use of a third party HTTP agent such as
+[proxy-agent](https://github.com/TooTallNate/node-proxy-agent). You can visit
+[npmjs.org](http://npmjs.org) for a list of other proxy libraries.
 
 ##### Installation
+
 ```javascript
 npm install proxy-agent --save
 ```
+
 ##### In your code
 
 ```javascript
 var proxy = require('proxy-agent');
-var proxyURI = process.env.http_proxy || 'http://internal.proxy.com'
-var proxyAgent = proxy(proxyURI);
 
 AWS.config.update({
-  httpOptions : {
-    agent: proxyAgent
-  }
+  httpOptions: { agent: proxy('http://internal.proxy.com') }
 });
 
 var s3 = new AWS.S3();