// this script from http://www.openspc2.org/JavaScript/Ajax/Ajax_study/chapter02/008/sample1/xmlhttp.js

// HTTP通信用、共通関数
function createXMLHttpRequest(cbFunc){
  
  var XMLhttpObject = null;
  
  try{
    XMLhttpObject = new XMLHttpRequest();
  } catch(e){
    try{
      XMLhttpObject = new ActiveXObject("Msxml2.XMLHTTP");
    } catch(e){
      try{
        XMLhttpObject = new ActiveXObject("Microsoft.XMLHTTP");
      }catch(e){
        return null;
      }
    }
  }
  
  if (XMLhttpObject) XMLhttpObject.onreadystatechange = cbFunc;
  return XMLhttpObject;
  
}