//
// Define a list of Microsoft XML HTTP ProgIDs.
//
var XMLHTTPREQUEST_MS_PROGIDS = new Array(
  "Msxml2.XMLHTTP.7.0",
  "Msxml2.XMLHTTP.6.0",
  "Msxml2.XMLHTTP.5.0",
  "Msxml2.XMLHTTP.4.0",
  "MSXML2.XMLHTTP.3.0",
  "MSXML2.XMLHTTP",
  "Microsoft.XMLHTTP"
);

//
// Define ready state constants.
//
var XMLHTTPREQUEST_READY_STATE_UNINITIALIZED = 0;
var XMLHTTPREQUEST_READY_STATE_LOADING       = 1;
var XMLHTTPREQUEST_READY_STATE_LOADED        = 2;
var XMLHTTPREQUEST_READY_STATE_INTERACTIVE   = 3;
var XMLHTTPREQUEST_READY_STATE_COMPLETED     = 4;

//
// Returns XMLHttpRequest object.
//
function getXMLHttpRequest()
{
  var httpRequest = null;

  // Create the appropriate HttpRequest object for the browser.
  if (window.XMLHttpRequest != null)
    httpRequest = new window.XMLHttpRequest();
  else if (window.ActiveXObject != null)
  {
    // Must be IE, find the right ActiveXObject.
    var success = false;
    for (var i = 0;
         i < XMLHTTPREQUEST_MS_PROGIDS.length && !success;
         i++)
    {
      try
      {
        httpRequest = new ActiveXObject(XMLHTTPREQUEST_MS_PROGIDS[i]);
        success = true;
      }
      catch (ex)
      {}
    }
  }

  // Display an error if we couldn't create one.
  if (httpRequest == null)
    alert("Error in HttpRequest():\n\n"
      + "Cannot create an XMLHttpRequest object.");

  // Return it.
  return httpRequest;
}


var cityStateLookup = getXMLHttpRequest();

function initiateCityStateLookup(event)
{
  // Get the zip code.
  var zipcode = document.registerform.elements["zipcode"].value;

  // Make a request to get the matching city and state.
  var url = "/ajax/zipcode/" + zipcode;
  cityStateLookup.open("GET", url, false);
  cityStateLookup.send(null);

  try
  {
    var data = cityStateLookup.responseText.split(",");
    if (data.length == 1)
    {
      document.registerform.elements["city"].value  = data[0];
    }
  }
  catch (ex)
  {}
}