Javascript/.nodeValue

var s1Val;
var s1ValCurrent;
var s1Count;
var s1Div = document.getElementById("s1Div");
s1Val = s1Div.firstChild.nodeValue;

function s1Func() {
  s1ValCurrent = s1Div.firstChild.nodeValue;
  if(s1ValCurrent.length == s1Val.length ){
    s1Div.innerHTML = '';
    s1Count = 0;
  }
  s1Div.innerHTML = s1Val.substr(0, ++s1Count);
  setTimeout('s1Func()', 400);
}