title: NS_Error_Failure on Javascript POST
body: <p>I am having trouble with some javascript. The code snippet below creates a simple post request however it always throws an <code>NS_Error_failure</code> exception (details at the bottom of the page). Can anyone tell me whats wrong with this code?</p>
  
  <p></p>
  
  <pre><code>window.onload = function () {
  
      alert('0');
      try {
          var url = "Some URL";
          var request = CreateHttpRequest();
          if (request) {
              alert('1');
              request.open("POST", url, false);
              request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
              alert('2');
              request.send('');
              alert('3');
          }
      }
      catch (err) {
          alert(err);
      }
  }
  </code></pre>
  
  <p></p>
  
  <pre><code>    [Exception... "Component returned failure code: 0x80004005 (NS_ERROR_FAILURE)"
       nsresult: "0x80004005 (NS_ERROR_FAILURE)"  
       location: "JS frame :: file:///C:/Users/Ben/Desktop/test.html :: &lt;TOP_LEVEL&gt; :: line 44"  data: no]
  </code></pre>