title: Jquery, No X-Requested-With=XMLHttpRequest in ajax request header?
body: <p><strong>SOME TIMES</strong> there is no X-Requested-With header, sometimes there is.</p>
  
  <p>I checked in firebug and found that, don't know why.</p>
  
  <p>So when I use request.is_ajax in django, it fails sometimes.</p>
  
  <p>Anyone know how to fix it?</p>
  
  <hr>
  
  <p>OK, now it happened again.
  I opened the page and then left for supper for <strong>a long while</strong>, when I came back, it happened again. I recorded request header in firbugs:</p>
  
  <p>Request with X-Requested-with:</p>
  
  <blockquote>
    <p>Host  localhost:8000<br /> User-Agent Mozilla/5.0 (Windows; U; Windows
    NT 5.2; zh-CN; rv:1.9.1.5) Gecko/20091102 <br /> Firefox/3.5.5<br />
    Accept    text/html, <em>/</em><br /> Accept-Language    zh-cn,zh;q=0.5<br />
    Accept-Encoding   gzip,deflate<br />
    Accept-Charset    GB2312,utf-8;q=0.7,*;q=0.7<br /> Keep-Alive 300<br />
    Connection    keep-alive<br /> X-Requested-With   XMLHttpRequest<br />
    Referer   <code>http://localhost:8000/gallery/</code><br /> Cookie    xxx<br /></p>
  </blockquote>
  
  <p>Request without X-Requested-with:</p>
  
  <blockquote>
    <p>Host  localhost:8000<br />
    User-Agent    Mozilla/5.0 (Windows; U;
    Windows NT 5.2; zh-CN; rv:1.9.1.5)
    Gecko/20091102 <br /> Firefox/3.5.5
    Accept    text/html,application/xhtml+xml,application/xml;q=0.9,<em>/</em>;q=0.8 Accept-Language    zh-cn,zh;q=0.5 Accept-Encoding    gzip,deflate<br />
    Accept-Charset    GB2312,utf-8;q=0.7,*;q=0.7<br /> Keep-Alive 300<br />
    Connection    keep-alive<br />
    Referer   <code>http://localhost:8000/gallery/</code><br/> 
    Cookie    xxx<br /></p>
  </blockquote>