var headTag    = document.getElementsByTagName('head')[0];

var link       = document.createElement('link');
    link.id    = 'authcss';
    link.rel   = 'stylesheet';
    link.type  = 'text/css';
    link.href  = '//www.sostav.ru/css/authorization_forms/default.css';
    link.media = 'all';

headTag.appendChild(link);

var req = new JsHttpRequest();
req.onreadystatechange = function() {
    if(req.readyState == 4) {
      document.getElementById('user_authorization_form').innerHTML = req.responseText;        
    }
}
req.open('POST', '/ajax/authorization/user_authorization_form.php', true);
req.send( { page: 'default' } );

function def_logout()
{
     var req = new JsHttpRequest();
     req.onreadystatechange = function()
     {
         if(req.readyState == 4)             
           location.reload();
     }
     req.open('POST', '/ajax/authorization/auth.php', true);
     req.send( { activator: 'exitUser', page: '' } ); 
}