nsixmlhttprequest

How do you submit an authenticated HTML form using XUL (Firefox extension) Javascript?

I am working on a Firefox extension, and in that extension I am trying to use AJAX to submit a form on a webpage. I am using: var request = Components.classes["@mozilla.org/xmlextras/xmlhttprequest;1"].createInstance(Components.interfaces.nsIXMLHttpRequest); request.onload = loadHandler; request.open("POST", url, true); request.send(va...