vlaajax = function () { }
/**
* Hack IE to avoid HTTP Get cache problems
*
* @param String Url
*/
vlaajax.AntiCacheRand = function (aurl) {
    var rnd = encodeURI(Math.random());
    aurl += (aurl.indexOf("?") >= 0) ? "&foo=" + rnd : "?foo=" + rnd;

    return aurl;
};

/**
* Create HttpRequest.
* This request allow us to communicate with the server
*
* @return HttpRequest
*/
vlaajax.CreateHttpRequest = function () {
    if (window.XMLHttpRequest) { // Mozilla, Safari,...
        http_request = new XMLHttpRequest();

        if (http_request.overrideMimeType) {
            http_request.overrideMimeType('text/html');
        }
    }
    else
        if (window.ActiveXObject) { // IE
            try {
                http_request = new ActiveXObject("Msxml2.XMLHTTP");
            }
            catch (e) {
                try {
                    http_request = new ActiveXObject("Microsoft.XMLHTTP");
                }
                catch (e) {
                }
            }
        }

    if (!http_request) {
        alert('Giving up :( Cannot create an XMLHTTP instance');
        return false;
    }

    return http_request;
};
/*
function updatea data
*/
var http_request = vlaajax.CreateHttpRequest();

function updateData(bac, trung, nam, lang) {
    var myurl = ['nxbgd/ajaxpages/ajax.aspx'];
    http_request.open("GET", myurl + "?idBac=" + escape(bac) + "&idTrung=" + escape(trung) + "&idNam=" + escape(nam) + "&lang=" + escape(lang), true);
    http_request.onreadystatechange = useHttpResponse;
    http_request.send(null);
}
/*
Hàm dữ liệu sử lý khi thành công ajaxrequest
*/
function useHttpResponse() {
    var loadstatustext = " <img src='nxbgd/resources/script/ajax.gif'/>";
    document.getElementById('div_mienbac').innerHTML = loadstatustext;
    if (http_request.readyState == 4) {
        var textout = http_request.responseText;
        //  alert(textout);
        var arr = textout.split('%');
        var element = getelement('div_mienbac');
        if (element != null) {
            //  alert(arr[1].length);
            // if (arr[1].length > 50)//tuc la co du lieu
            element.innerHTML = arr[1];
            // if (arr[2].length > 50)//tuc la co du lieu
            getelement('div_mientrung').innerHTML = arr[2];
            //if(arr[3].length>50)//tuc la co du lieu
            getelement('div_miennam').innerHTML = arr[3];
        }
    } else {
        //Trường hợp đứt mạng lưu vào cookies hoạc hidenfied
    }
}
/**
* Get HtmlControl reference
*
* note: this is a static method, Misc Class
* doesn't have to be instantiated
*
* @param String
* @return Element object
*/
$ = function (element) {
    if (document.getElementById) {
        return document.getElementById(element);
    }
};
function getelement(element) {
    if (document.getElementById) {
        return document.getElementById(element);
    }
};
function getQuerystring(key, default_) {
    if (default_ == null) default_ = "";
    key = key.replace(/[\[]/, "\\\[").replace(/[\]]/, "\\\]");
    var regex = new RegExp("[\\?&]" + key + "=([^&#]*)");
    var qs = regex.exec(window.location.href);
    if (qs == null)
        return default_;
    else
        return qs[1];
}