function getObject(obj) {
  var theObj;
  if(document.all) {
    if(typeof obj=="string") {
      return document.all(obj);
    } else {
      return obj.style;
    }
  }
  if(document.getElementById) {
    if(typeof obj=="string") {
      return document.getElementById(obj);
    } else {
      return obj.style;
    }
  }
  return null;
}

function setCounter(field_id, maxchars, span_id) {
	var fieldObj = getObject(field_id);
	var spanObj = getObject(span_id);
	var charsLeft = maxchars - fieldObj.value.length;
	
	if (charsLeft <= 0) {
		spanObj.innerHTML = "<font color='#FF0000'>0</font>";
	} else {
		spanObj.innerHTML = charsLeft;
	}
}