ajax = false;

if (window.XMLHttpRequest)
{
  ajax = new XMLHttpRequest();
}
else if (window.ActiveXObject) 
{
  try {
    ajax = new ActiveXObject("Msxml2.XMLHTTP");
  } catch (e) {
    ajax = new ActiveXObject("Microsoft.XMLHTTP");
  }
}

function getTextData(requestURL, objName)
{
  ajax.open("GET", requestURL);

  ajax.onreadystatechange = function() {
    if (ajax.readyState == 4 && ajax.status == 200) {
      setSelectObject(objName, ajax.responseText);
    }
  }
  ajax.send(null);
}