function getCookie(name)
{
  var prefix = name + "=";
  var start = document.cookie.indexOf(prefix);
  if (-1 == start)
    return null
  var end = document.cookie.indexOf(";", start + prefix.length);
  if (-1 == end)
    end = document.cookie.length;
  var value = document.cookie.substring(start + prefix.length, end);
  return unescape(value);  
}

function setCookie(name, value, expires, path, domain, secure)
{
  var newCookie = name + "=" + escape(value) + 
    ((expires)   ? ";expires=" + expires.toGMTString():"")+
    ((path)     ? ";path="    + path                 :"")+
    ((domain)   ? ";domain="  + domain               :"")+
    ((secure)   ? ";secure"                          :"");

  document.cookie = newCookie;
}

function deleteCookie(name, path, domain)
{
  if (getCookie(name))
  {
    document.cookie = name + "=" +
    ";expires=Thu,01-Jan-70 00:00:01 GMT" + 
    ((path)     ? ";path="    + path                 :"")+
    ((domain)   ? ";domain="  + domain               :"");
  }
}