// JavaScript Document
function createXmlHttpRequestObject(){
  //creates XMLHttpRequest object if it is possible
  var xmlhttp
  try {
    //should work on all browsers except IE6 or older
    xmlHttp = new XMLHttpRequest();
  }
  catch (e){
    //browser is IE6 or older
    try {
      xmlHttp = new ActiveXObject("Microsoft.XMLHttp");
    }
    catch (e){
    //ignore error
    }
  }
  if (!xmlHttp)
    alert ("Error creating the XMLHttpRequest object.");
  else
    return xmlHttp;
}

function setRegion(idRegion) {

  var http_request = createXmlHttpRequestObject();
  var request = 'region=' + idRegion;

  http_request.onreadystatechange = function() {
    setRegionResponse(http_request);
  };
  
  http_request.open('POST', "http://" + window.location.hostname + '/ajax/setRegion.php');
  http_request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
  http_request.send(request);
}

function setRegionResponse(http_request) {
  if (http_request.readyState == 4) {
    if (http_request.status == 200) {
      location.reload(true);
    }
  }
}

function processSetLetter(letter) {
  var http_request = createXmlHttpRequestObject();
  var request = 'letter=' + letter;
  
  http_request.onreadystatechange = function() {
    processSetLetterResponse(http_request);
  };

  http_request.open('POST', "http://" + window.location.hostname + '/ajax/setFirstLetter.php');
  http_request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
  http_request.send(request);
}

function processSetLetterResponse(http_request) {
 if (http_request.readyState == 4) {
    if (http_request.status == 200) {
      var url = location.href;
      var regExp = /\/[0-9]+\/$/;
      url = url.replace(regExp, "/");
      window.location.href = url;
    }
 }
}