function postar(url){
  var form = document.forms['form_login_topo'];
  if (url != '') {
  form.action=url;
  }
  form.submit();
}
/** da post no ajax **/
var TRYLON = undefined;
function logar_topo(login,senha)
{
    if (TRYLON != undefined) return false;
    var handler = new XMLHandler();
    var xmlreq = new XMLClient(URLLOGINAUT);
    xmlreq.setAsync(false);
    xmlreq.addParam('login', login);
    xmlreq.addParam('senha', senha);
    handler.onError = function (e) { alert(e)}
    handler.onProgress = function () {}
    handler.onInit = function () {}
    handler.onLoad = function (xml)
    {
        TRYLON = undefined;
        if (xml != '')
        {
            if (xml == 'logou')
            {
                postar('');
            } else {
                alert('Login ou senha inválidos');
            }
        }
        return false;
    }
    TRYLON = 1;
    xmlreq.query(handler);
    return false;
}