var url = "getTags.php?param="; // The server-side script
function handleHttpResponse() {
  if (http.readyState == 4) {
    if (http.responseText.indexOf('invalid') == -1) {
      // Use the XML DOM to unpack the city and state data
      var xmlDocument = http.responseXML;
      var tag = xmlDocument.getElementsByTagName('tag').item(0).firstChild.data;
      document.getElementById('tag').value = tag;
      isWorking = false;
    }
  }
}
var isWorking = false;
function updateTags() {
  if (!isWorking && http) {
    var usernameValue = document.getElementById("username").value;
    http.open("GET", url + escape(usernameValue), true);
    http.onreadystatechange = handleHttpResponse;
    isWorking = true;
    http.send(null);
  }
}
function getHTTPObject() {
  var xmlhttp;
  /*@cc_on
  @if (@_jscript_version >= 5)
    try {
      xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
    } catch (e) {
      try {
        xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
      } catch (E) {
        xmlhttp = false;
      }
    }
  @else
  xmlhttp = false;
  @end @*/
  if (!xmlhttp && typeof XMLHttpRequest != 'undefined') {
    try {
      xmlhttp = new XMLHttpRequest();
	  xmlhttp.overrideMimeType("text/xml");
    } catch (e) {
      xmlhttp = false;
    }
  }
  return xmlhttp;
}
var http = getHTTPObject(); // We create the HTTP Object