// ==UserScript==
// @name          UserStyles.org login form
// @namespace     http://loucypher.wordpress.com/
// @include       http://userstyles.org/*
// @description	  Login form/logout link on every page
// ==/UserScript==

var header = document.getElementsByTagName('h1')[0];

var login = document.evaluate('//ul[@id="navigation"]/li[position()=3]/a',
  document, null, 0, null).iterateNext();

if(login && login.href.match(/\/login/)) {
  var formElm = '\
  <input type="text" name="login" id="username" value="username" onfocus="this.value=\'\'" />\
  <input type="password" name="password" id="password" value="password" onfocus="this.value=\'\'" />\
  <input type="submit" value="login" />';

  var form = document.createElement('form');
  form.method = 'post';
  form.action = '/login/authenticate';
  form.setAttribute('autocomplete', 'on');
  form.setAttribute('style', 'float: right; margin-top: 2em; font-size: small;');
  form.innerHTML = formElm;

  header.parentNode.insertBefore(form, header);

} else {
  var logout = document.createElement('a');
  logout.href = '/logout';
  logout.setAttribute('style', 'float: right; font-size: small;');
  logout.appendChild(document.createTextNode('Log out'));
  header.insertBefore(logout, header.firstChild);
}