function GetXmlHttpObject(handler)
{
  var objXmlHttp = null

  if (navigator.userAgent.indexOf("Opera") >= 0)
  {
    alert("Sorry, but we don't support the Opera browser.");
    return;
  }
  if (navigator.userAgent.indexOf("MSIE")>=0)
  {
    var strName = "Msxml2.XMLHTTP";
    if (navigator.appVersion.indexOf("MSIE 5.5") >= 0)
      strName = "Microsoft.XMLHTTP";
    try
    {
      objXmlHttp = new ActiveXObject(strName);
      objXmlHttp.onreadystatechange = handler;
      return objXmlHttp;
    }
    catch(e)
    {
      alert("Error. Scripting for ActiveX might be disabled");
      return;
    }
  }
  if (navigator.userAgent.indexOf("Mozilla") >= 0)
  {
    objXmlHttp = new XMLHttpRequest();
    objXmlHttp.onload = handler;
    objXmlHttp.onerror = handler;
    return objXmlHttp;
  }
}

var xmlHttp = null;
var saveContent = null;

function processLogin()
{
  try
  {
    var form = document.forms["login"];
    var email = form["email"].value;
    var pwd = form["pwd"].value;
    var elem = document.getElementById("login");
    saveContent = elem.innerHTML;
    elem.innerHTML = "Logging in, please wait...";
    var url = "processLogin.php?sid=" + Math.random() + "&email=" + email + "&pwd=" + pwd;
    xmlHttp = GetXmlHttpObject(processLoginAJAX);
    xmlHttp.open("GET", url , true);
    xmlHttp.send(null);
  }
  catch (e)
  {
    alert("problem: " + e);
    throw e;
  }
}

function processLoginAJAX()
{
  if ((xmlHttp.readyState == 4) || (xmlHttp.readyState == "complete"))
  {
    var data = xmlHttp.responseText;
    if (data.indexOf("-") >= 0)
    {
      var elem = document.getElementById("login");
      elem.innerHTML = saveContent;
      elem = document.getElementById("login_error");
      elem.innerHTML = "<font bgcolor=\"#FF0000\" size=\"-1\">Unknown email and/or password<br/>Please try again...</font>";
    }
    else
      location.reload(true);
  }
}

function logout()
{
  var url = "logout.php?sid=" + Math.random();
  xmlHttp = GetXmlHttpObject(logoutAJAX);
  xmlHttp.open("GET", url , true);
  xmlHttp.send(null);
}

function logoutAJAX()
{
  if ((xmlHttp.readyState == 4) || (xmlHttp.readyState == "complete"))
    location.reload(true);
}