// HTTPRequest Object
var httpObj ;
var timerID ;

// set Ajax object(global ajax object is httpObj)
function createXMLHttpRequest(onreadystatechangeFunc)
{
    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 = onreadystatechangeFunc;
    return XMLhttpObject;
}

// Timer
function httpObjAbort()
{
    httpObj.abort();
}

function $(tagId)
{
    return document.getElementById(tagId);
}