function GetElementById(id)
{
  if (typeof(id) != 'string')
    return null;
  if (document.getElementById)
    return document.getElementById(id);
  if (document.all)
   return document.all[id];
  return null;
}

function GetCookie(name)
{
  var arg = name + "=";
  var alen = arg.length;
  var clen = document.cookie.length;
  var val = null;
  var i = 0;
  while (i < clen)
  {
    var j = i + alen;
    if (document.cookie.substring(i, j) == arg)
    {
      val = getCookieVal (j);
      break;
    }
    i = document.cookie.indexOf(" ", i) + 1;
    if (i == 0)
      break;
  }
  return val;
}

function getCookieVal (offset)
{
  var endstr = document.cookie.indexOf (";", offset);
  if (endstr == -1)
    endstr = document.cookie.length;
  return unescape(document.cookie.substring(offset, endstr));
}

function SetCookie (name, value)
{
  document.cookie = name + "=" + escape(value);
}

function DeleteCookie (name)
{
  var exp = new Date();
  exp.setTime (exp.getTime() - 1);
  var cval = GetCookie (name);
  document.cookie = name + "=" + cval + "; expires=" + exp.toGMTString();
}