function getDataReturnText(url, callback)
{ 
  var XMLHttpRequestObject = false; 

  if (window.XMLHttpRequest) {
    XMLHttpRequestObject = new XMLHttpRequest();
  } else if (window.ActiveXObject) {
    XMLHttpRequestObject = new 
     ActiveXObject("Microsoft.XMLHTTP");
  }

  if(XMLHttpRequestObject) {
    XMLHttpRequestObject.open("GET", url); 

    XMLHttpRequestObject.onreadystatechange = function() 
    { 
// I added this
if(XMLHttpRequestObject.readyState != 4) {
document.getElementById('throbber').style.display = 'inline';
}
if(XMLHttpRequestObject.readyState == 4) {
document.getElementById('throbber').style.display = 'none';
}
// I added this
      if (XMLHttpRequestObject.readyState == 4 && 
        XMLHttpRequestObject.status == 200) { 
          callback(XMLHttpRequestObject.responseText); 
          delete XMLHttpRequestObject;
          XMLHttpRequestObject = null;
      } 
    } 

    XMLHttpRequestObject.send(null); 
  }
}

function postDataReturnText(url, data, callback)
{ 
  var XMLHttpRequestObject = false; 

  if (window.XMLHttpRequest) {
    XMLHttpRequestObject = new XMLHttpRequest();
  } else if (window.ActiveXObject) {
    XMLHttpRequestObject = new 
     ActiveXObject("Microsoft.XMLHTTP");
  }

  if(XMLHttpRequestObject) {
    XMLHttpRequestObject.open("POST", url); 
    XMLHttpRequestObject.setRequestHeader('Content-Type', 
      'application/x-www-form-urlencoded'); 
    XMLHttpRequestObject.onreadystatechange = function() 
    { 
// I added this
if(XMLHttpRequestObject.readyState != 4 && document.getElementById("throbber")) {
document.getElementById('throbber').style.display = 'inline';
}
if(XMLHttpRequestObject.readyState == 4 && document.getElementById("throbber")) {
document.getElementById('throbber').style.display = 'none';
}
// I added this
      if (XMLHttpRequestObject.readyState == 4 && 
        XMLHttpRequestObject.status == 200) {
          callback(XMLHttpRequestObject.responseText); 
          delete XMLHttpRequestObject;
          XMLHttpRequestObject = null;
      } 
    }

    XMLHttpRequestObject.send(data); 
  }
}