function rnd_code(length) {
  var chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
  var pass = "";
  for(var i=0;i<length;i++)
  {
    pass += chars.charAt(Math.floor(Math.random() * 62));
  }
  return pass;
}
function qet_param() {
  var query = window.location.search.substring(1);
  var parms = query.split('&');
  for (var i=0; i<parms.length; i++) {
    var pos = parms[i].indexOf('=');
    if (pos > 0) {
      var key = parms[i].substring(0,pos);
      var val = parms[i].substring(pos+1);
      if (key=="emp_ref") return val;
    }
  }
  return null;
}
function create_cookie(name,value,days) {
  if (days) {
    var date = new Date();
    date.setTime(date.getTime()+(days*24*60*60*1000));
    var expires = "; expires="+date.toGMTString();
  }
  else var expires = "";
  document.cookie = name+"="+value+expires+"; path=/";
}
function read_cookie(name) {
  var nameEQ = name + "=";
  var ca = document.cookie.split(';');
  for(var i=0;i < ca.length;i++) {
    var c = ca[i];
    while (c.charAt(0)==' ') c = c.substring(1,c.length);
    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
  }
  return null;
}

var emp_em = qet_param();

if (emp_camp && (emp_em!==null) && (read_cookie("emp_"+emp_camp)===null)) {
  var emp_code = rnd_code(32);
  create_cookie("emp_"+emp_camp,emp_code,2);
  var emp_img = new Image(1,1);
  emp_img.src = "http://www.empressive.com/ext/optin_code.php?camp="+emp_camp+"&em="+emp_em+"&code="+emp_code;
};