title: xmlhttprequest simultaneous request not working
body: <p>I'm trying to make "many" <em>xhr</em> request but it seems that every time it waits for the answer before making another request. It's like <em>XHR</em> makes a queue and always wait for the previous request to finish. </p>
  
  <p>What can I do to run more simultaneous <em>xhr</em> request?</p>
  
  <pre><code>$('body').delegate('.download','click', function(evt){
          evt.preventDefault(); // Not related
  
          var xhr = new XMLHttpRequest();
          xhr.open('GET', "proxy.php?" + this.href, true);
          xhr.responseType = 'blob';
  
          xhr.onload = function() {
              if (this.status == 200) {              
                  var blob = new Blob([this.response], {type:'audio/mp4'});
  
                  console.log(blob.size);
                  if(blob.size &gt; 0){
                      $("&lt;a&gt;").attr({
                          download: name,
                          href: URL.createObjectURL(blob),
                          target: "_blank"
                      })[0].click();
                  }
              }
          };  
          xhr.send();
      });
  </code></pre>