title: ConfigurationManager - How to use connection strings with .NET 3.5?
body: <p>I see a very good post here about what I am wanting to do,</p>
  
  <p><a href="https://stackoverflow.com/questions/1831291/net-3-5-to-read-connectionstring-from-app-config">.net 3.5: To read connectionstring from app.config?</a></p>
  
  <p>It says to use the ConfigurationManager class. I cannot reference the ConfigurationManager class.</p>
  
  <p>If I look at the system.dll that I am using (which is v2.0.50727) there is no ConfigurationManager class.</p>
  
  <p>I am using VS 2008, and my project is set to compile as .NET 3.5.</p>
  
  <p>If I do this,</p>
  
  <pre><code>string test = System.Configuration.ConfigurationManager.AppSettings["test"];
  </code></pre>
  
  <p>I get the message 'Error    182 The type or namespace name 'ConfigurationManager' does not exist in the namespace 'System.Configuration' (are you missing an assembly reference?)'</p>
  
  <p>Any ideas?</p>