function replaceText(el, text) {
   if (el != null) {
      clearText(el);
      var newNode = document.createTextNode(text);
      el.appendChild(newNode);
   }
}

function clearText(el) {
   if (el != null) {
      if (el.childNodes) {
         for (var i = 0; i < el.childNodes.length; i++) {
            var childNode = el.childNodes[i];
            el.removeChild(childNode);
         }
      }
   }
}

function getText(el) {
   var text = "";
     if (el != null) {
          if (el.childNodes) {
               for (var i = 0; i < el.childNodes.length; i++) {
            var childNode = el.childNodes[i];
            if (childNode.nodeValue != null) {
               text = text + childNode.nodeValue;
            }
         }
      }
   }
   return text;
}