-pname.xpi

-chrome
--pname.jar
-install.rdf
-chrome.manifest

-pname
--content
---pname.xul
---pname.js

<?xml version="1.0"?>
<RDF xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
     xmlns:em="http://www.mozilla.org/2004/em-rdf#">

  <Description about="urn:mozilla:install-manifest">

    <em:id>f-l@bk.ru</em:id>
    <em:name>pname</em:name>
    <em:version>0.1</em:version>
    <em:description>pname</em:description>
    <em:creator>pname</em:creator>
    

    
    <em:homepageURL>null</em:homepageURL>
    
   
    <em:targetApplication>
      <Description>
        <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id>
        <em:minVersion>1.5</em:minVersion>
        <em:maxVersion>3.0.*</em:maxVersion>
      </Description>
    </em:targetApplication>

  </Description>

</RDF>

content    pname    jar:chrome/pname.jar!/content/
overlay    chrome://browser/content/browser.xul chrome://pname/content/pname.xul

<?xml version="1.0"?>
<overlay id="pname-Overlay"  xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
<script type="application/x-javascript"  src="chrome://pname/content/pname.js"/>
</overlay>

function pnload(event)
{
alert('load');
}
window.addEventListener('DOMContentLoaded', pnload , false);
alert('pname loaded');