title: jquery ajax error {"readyState":0,"responseText":"","status":0,"statusText":"error"}
body: <p>I am trying to do an ajax request</p>
  
  <pre><code>$.ajax({
    type: "post",
    url: "download.php",
    error: function(data, status, err){
             alert(JSON.stringify(data));
           },
    data: "fileid="+fileid
  });
  </code></pre>
  
  <p>this request alerts "{"readyState":0,"responseText":"","status":0,"statusText":"error"}"</p>
  
  <p>I have searched on google all i have come up with is a cross site ajax call(which this is obviously not)</p>
  
  <p>I have tried putting the full url in and it does the same thing.</p>
  
  <p>the only thing i can think of is the header and i don't know what would be wrong with it. Here is the request header from firebug</p>
  
  <pre><code>Host                www.mydomain.com
  User-Agent          Mozilla/5.0 (Windows NT 6.1; rv:5.0) Gecko/20100101 Firefox/5.0
  Accept              */*
  Accept-Language     en-us,en;q=0.5
  Accept-Encoding     gzip, deflate
  Accept-Charset      ISO-8859-1,utf-8;q=0.7,*;q=0.7
  Connection          keep-alive
  Content-Type        application/x-www-form-urlencoded; charset=UTF-8
  X-Requested-With    XMLHttpRequest
  Referer             http://www.mydomain.com/
  Content-Length      8
  Cookie              PHPSESSID=27b7d3890b82345a4fc9604808acd928
  </code></pre>
  
  <p>I have added another request on a different page and it works just fine but this one keeps failing the header for the other request is:</p>
  
  <pre><code>Host                www.mydomain.com
  User-Agent          Mozilla/5.0 (Windows NT 6.1; rv:5.0) Gecko/20100101 Firefox/5.0
  Accept              text/plain, */*; q=0.01
  Accept-Language     en-us,en;q=0.5
  Accept-Encoding     gzip, deflate
  Accept-Charset      ISO-8859-1,utf-8;q=0.7,*;q=0.7
  Connection          keep-alive
  Content-Type        application/x-www-form-urlencoded; charset=UTF-8
  X-Requested-With    XMLHttpRequest
  Referer             http://www.mydomain.com/differentpage.php
  Content-Length      33
  Cookie              PHPSESSID=27b7d3890b82345a4fc9604808acd928
  </code></pre>