****** index.html

<html>
    <head>
    </head>
    <body>
        <script>
            var dude = new Worker('my_worker.js');
            dude.onmessage = function(e) {
                alert(e.data);
            };
            dude.postMessage('fire');
        </script>
    </body>
</html>


****** my_worker.js

makeRequest = function() {
    var req = new XMLHttpRequest();
    
    req.open('GET', 'http://www.google.com/');
        
    req.onreadystatechange = function (e) {
      if (req.readyState == 4) {
         postMessage("received status: "+req.status);
      }
    };

    req.send(null);
};

onmessage = function(e) {
    makeRequest();
};


****** the error

uncaught exception: [Exception... "Component returned failure code: 0x805e000a [nsIXMLHttpRequest.open]" nsresult: "0x805e000a (<unknown>)" location: "JS frame :: file:///usr/home/pope/hx/my_worker.js :: anonymous :: line 4" data: no]


