function listenlight() {

 var timer = setTimeout("setInterval('textengine();', 90);", 1500);
 var clear = setTimeout("clearTimeout(timer);", 20000);
}


          var letter = 0;
          var textstringlength = 70;
          function textengine() {
              if( letter < textstringlength ) {
                if( document.getElementById("n" + letter).innerHTML == "_" )
                  document.getElementById("n" + letter).innerHTML="&nbsp;";
                else {
                  document.getElementById("n" + letter++).style.visibility="visible";
                }
                return true; 
              }
            return false;
          }