var sent = new Array();

function foo() {
 alert('test in detect');
}

function get_array_key(pvid, msid, fpos, bpos) {
 return pvid + '.' + msid + '.' + fpos + '.' + bpos;
}

function send_detect(pvid, msid, fpos, bpos, session_id) {
  var ps = '?pvid=' + pvid + '&msid=' + msid + '&fpos=' + fpos + '&bpos=' + bpos + '&_session_id=' + session_id;
  var img = new Image();
  img.src = '/detect' + ps;
}

function send_detect_if_necessary(pvid, msid, fpos, bpos, session_id) {
  //alert('foo');
  key = get_array_key(pvid, msid, fpos, bpos);

  if (sent[key]) {
    // do nothing
  } else {
    send_detect(pvid, msid, fpos, bpos, session_id);
    sent[key] = true;
  }
}

function track_afs_results(pvid, bpos, res, session_id) {
  var ps = '?pvid=' + pvid + '&bpos=' + bpos + '&res=' + res + '&_session_id=' + session_id;
  var img = new Image();
  img.src = '/afs' + ps;
}