title: The type or namespace name 'Ajax' could not be found
body: <p>I got an old project which consist of three different projects. When I am trying to build the project I am getting this error message: </p>
  
  <pre><code>"The type or namespace name 'Ajax' could not be found (are you missing a using    
  directive or an assembly reference?)" 
  </code></pre>
  
  <p>I have found solution for missing project or namespace online but it looks like I am missing some default library.</p>
  
  <p>The code looks like this:</p>
  
  <pre><code>//Ajax method to Check for existing file name
  [Ajax.AjaxMethod()]
  public DataTable CheckSearchName(string searchname){
     // code goes here
  }
  </code></pre>
  
  <p>Any help?</p>