function fillReferrer() {
  if ( document.referrer ) {
    var formsList = document.forms;
    for ( var i=0; i<formsList.length; i++ ) {
      if ( formsList[i].referrer && formsList[i].referrer.value == '' )
        formsList[i].referrer.value = document.referrer;
      else
      if ( !formsList[i].referrer ) {
        var el = document.createElement("input");
        el.type = "hidden";
        el.name = "referrer";
        el.value = document.referrer;
        formsList[i].appendChild(el);
      }
    }
  }
}