title: Error “Access-Control-Allow-Origin” header in asp.net
body: <p>I have 2 project are running parallel.
  <a href="http://localhost:497" rel="nofollow noreferrer">http://localhost:497</a> and <a href="http://localhost:580" rel="nofollow noreferrer">http://localhost:580</a></p>
  
  <p>On <a href="http://localhost:580" rel="nofollow noreferrer">http://localhost:580</a> I want to get file html form folder PDF in <a href="http://localhost:497" rel="nofollow noreferrer">http://localhost:497</a> into iframe</p>
  
  <pre><code>&lt;iframe src="http://localhost:497/PDF/test.html"&gt;&lt;/iframe&gt;
  </code></pre>
  
  <p>After that, i was received an error: </p>
  
  <blockquote>
    <p>XMLHttpRequest cannot load
    <a href="http://localhost:497/PDF/test.html" rel="nofollow noreferrer">http://localhost:497/PDF/test.html</a>. No
    'Access-Control-Allow-Origin' header is present on the requested
    resource. Origin '<a href="http://localhost:580" rel="nofollow noreferrer">http://localhost:580</a>' is therefore not allowed
    access.</p>
  </blockquote>
  
  <p>and I can't use jquery for get effect to content in iframe .</p>
  
  <p>I don't know how to fix that error, please help me. Thanks All.</p>