// call saveReferrerCookie() from your pages.

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

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

// Write the cookie to remember user only if the cookie is not on user's computer

function saveReferrerCookie() {
  todayDate = new Date;
  id = todayDate;
  id= todayDate.getTime(); 
  var ref="" +document.referrer;
  var se="" +document.location.search;
  var agt=""+document.agent;
  var url=""+document.URL;
  if(top.document.location==document.referrer || (document.referrer == '' && top.document.location != '')) {
    ref=""+top.document.referrer;
    se=""+top.document.location.search;
    agt=""+top.document.agent;
    url=""+top.document.URL;
  }
  s="ref="+ref;
  s+="&id="+id;
  s+="&agt="+agt;
  s+="&url="+url;
  s+="&se="+se;
  expireDate = new Date;
  expireDate.setMonth(expireDate.getMonth()+1);
  var id2 = GetCookie('SurfDetails');
  i = ref.indexOf(url);
  if ((i < 0) || (id2 == null))  {
    document.cookie = "SurfDetails="+s+";expires=" + expireDate.toGMTString();
  }
}