title: System.Net.SecurityProtocolType.Tls12 definition not found
body: <p>I'm trying to add the following line of code to the Global.asax file in a website project.</p>
  
  <pre><code>System.Net.ServicePointManager.SecurityProtocol = System.Net.SecurityProtocolType.Tls12;
  </code></pre>
  
  <p>The vs2012 IntelliSense is showing that Tls12 definition exist.  But the build is saying that the definition does not exist (See screen shot).  </p>
  
  <p><a href="https://i.stack.imgur.com/r8GMV.png" rel="noreferrer"><img src="https://i.stack.imgur.com/r8GMV.png" alt="screen shot"></a></p>
  
  <p>I've tried adding System.Net.dll to the bin folder of the project, but the build still failed.  Any idea how I might be able to resolve this?</p>