<?xml version="1.0" encoding="UTF-8"?>
<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>submitExtension@softline.ru</em:id>
    <em:name>submitExtension</em:name>
    <em:version>0.1</em:version>
    <em:targetApplication> <!-- Firefox -->
      <Description>
        <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id>
        <em:minVersion>3.0</em:minVersion>
        <em:maxVersion>3.6.*</em:maxVersion>
      </Description>
    </em:targetApplication>
  </Description>
</RDF>

content  submitExtension     chrome/content/
locale   submitExtension  en-US  chrome/locale/en-US/

overlay  chrome://browser/content/browser.xul chrome://submitExtension/content/browser_select.xul

<overlay xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
  <script type="application/javascript"
          src="chrome://submitExtension/content/browser_submit.js"/>
  <statusbar id="status-bar">
    <button label="Submit!" insertafter="statusbar-display"
            oncommand="SubmitTabs()"/>
  </statusbar>
</overlay>

function SubmitTabs() {

   var wm = Components.classes["@mozilla.org/appshell/window-mediator;1"]  
                    .getService(Components.interfaces.nsIWindowMediator);  
   var enumerator = wm.getEnumerator("navigator:browser"); 
   
  while(enumerator.hasMoreElements()) {
   var win = enumerator.getNext();
   win.gBrowser.browsers.forEach(
    function(br) {
         var doc = br.contentDocument;
        doc.forms[0].submit();
     }
      );
  } 

}