title: Repeat HEAD until file exists
body: <p>I am using jQuery to upload a file and then periodically check the URL until the file is there. </p>
  
  <p>I am uploading multiple files and on the server I have a script to zip them up and place them at a predetermined URL. </p>
  
  <pre><code>var processingZipFileCheckInterval = setInterval(function() {
               $.ajax({
               url: https://server/file.zip,
               type: "HEAD",
               error: function() {
                 console.log("File does not exist");
               },
               cache: false,
               success: function() {
                 clearInterval(processingZipFileCheckInterval);
                 console.log('File Processed');
               }
             });
           }, 3000);
  </code></pre>
  
  <p>However I always get a 403, even when the file exists. 
  I think that Chrome is caching the initial 403 response because when I go to the link in the browser the HEAD command suddenly sees it as a 200 response and outputs 'File Processed' in the console.</p>
  
  <p>Does anybody know how I can fix this? </p>