function GetCookie(sName)
{
  // cookies are separated by semicolons
  var aCookie = document.cookie.split("; ");
  for (var i=0; i < aCookie.length; i++)
  {
    // a name/value pair (a crumb) is separated by an equal sign
    var aCrumb = aCookie[i].split("=");
    if (sName == aCrumb[0]) 
      return unescape(aCrumb[1]);
  }

  // a cookie with the requested name does not exist
  return null;
}

function SetCookie( name, value, expiredays )
{
    if ( expiredays==undefined ) expiredays=30;

    var todayDate = new Date();
    todayDate.setDate(todayDate.getDate() + expiredays);
    document.cookie = name + "=" + escape(value) + "; expires=" + todayDate.toGMTString();
}

function DeleteCookie (name)
{
    var exp  = new Date();
    var cval = GetCookie (name);

    exp.setTime (exp.getTime() - 1);  // This cookie is history
    document.cookie = name + "=" + cval + "; expires=" + exp.toGMTString();
}