var Ajaxs = new Array();
var AjaxStacks = new Array(0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
var attackevasive = 1;
function Ajax(recvType, waitId) {
    for (var stackId = 0; stackId < AjaxStacks.length && AjaxStacks[stackId] != 0; stackId++);
    AjaxStacks[stackId] = 1;

    var aj = new Object();
    aj.loading = '请稍候，正在下载数据...'; //public
    aj.recvType = recvType ? recvType : 'XML'; //public
    aj.waitId = waitId ? $(waitId) : null; //public
    aj.resultHandle = null; //private
    aj.sendString = ''; //private
    aj.targetUrl = ''; //private
    aj.stackId = 0;
    aj.stackId = stackId;
    aj.setLoading = function(loading) {
        if (typeof loading !== 'undefined' && loading !== null) aj.loading = loading;
    }
    aj.setRecvType = function(recvtype) {
        aj.recvType = recvtype;
    }
    aj.setWaitId = function(waitid) {
        aj.waitId = typeof waitid == 'object' ? waitid : $(waitid);
    }
    aj.createXMLHttpRequest = function() {
        var request = false;
        if (window.XMLHttpRequest) {
            request = new XMLHttpRequest();
            if (request.overrideMimeType) {
                request.overrideMimeType('text/xml');
            }
        } else if (window.ActiveXObject) {
            var versions = ['Microsoft.XMLHTTP', 'MSXML.XMLHTTP', 'Microsoft.XMLHTTP', 'Msxml2.XMLHTTP.7.0', 'Msxml2.XMLHTTP.6.0', 'Msxml2.XMLHTTP.5.0', 'Msxml2.XMLHTTP.4.0', 'MSXML2.XMLHTTP.3.0', 'MSXML2.XMLHTTP'];
            for (var i = 0; i < versions.length; i++) {
                try {
                    request = new ActiveXObject(versions[i]);
                    if (request) {
                        return request;
                    }
                } catch (e) { }
            }
        }
        return request;
    }
    aj.XMLHttpRequest = aj.createXMLHttpRequest();
    aj.showLoading = function() { 
        if (aj.waitId && (aj.XMLHttpRequest.readyState != 4 || aj.XMLHttpRequest.status != 200)) {
            // changedisplay(aj.waitId, '');
           
            aj.waitId.innerHTML = '<span><img src="images/loading.gif"><br/>' + aj.loading + '</span>';
        }
    }
    aj.processHandle = function() {
        if (aj.XMLHttpRequest.readyState == 4 && aj.XMLHttpRequest.status == 200) {
            for (k in Ajaxs) {
                if (Ajaxs[k] == aj.targetUrl) {
                    Ajaxs[k] = null;
                }
            }
            //if (aj.waitId) changedisplay(aj.waitId, 'none');
            if (aj.recvType == 'HTML') {
                aj.resultHandle(aj.XMLHttpRequest.responseText, aj);
            } else if (aj.recvType == 'XML') {
                aj.resultHandle(aj.XMLHttpRequest.responseXML.lastChild.firstChild.nodeValue, aj);
            }
            AjaxStacks[aj.stackId] = 0;
        }
    }
    aj.get = function(targetUrl, resultHandle) {
        setTimeout(function() { aj.showLoading() }, 50);
        if (in_array(targetUrl, Ajaxs)) {
            return false;
        } else {
            Ajaxs.push(targetUrl);
        }
        aj.targetUrl = targetUrl;
        aj.XMLHttpRequest.onreadystatechange = aj.processHandle;
        aj.resultHandle = resultHandle;
        var delay = attackevasive & 1 ? (aj.stackId + 1) * 1001 : 100;
        if (window.XMLHttpRequest) {
            setTimeout(function() {
                aj.XMLHttpRequest.open('GET', aj.targetUrl);
                aj.XMLHttpRequest.send(null);
            }, delay);
        } else {
            setTimeout(function() {
                aj.XMLHttpRequest.open("GET", targetUrl, true);
                aj.XMLHttpRequest.send();
            }, delay);
        }
    }
    aj.post = function(targetUrl, sendString, resultHandle) {
        setTimeout(function() { aj.showLoading() }, 50);
        if (in_array(targetUrl, Ajaxs)) {
            return false;
        } else {
            Ajaxs.push(targetUrl);
        }
        aj.targetUrl = targetUrl;
        aj.sendString = sendString;
        aj.XMLHttpRequest.onreadystatechange = aj.processHandle;
        aj.resultHandle = resultHandle;
        aj.XMLHttpRequest.open('POST', targetUrl);
        aj.XMLHttpRequest.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
        aj.XMLHttpRequest.send(aj.sendString);
    }
    return aj;
}

function createXMLHttp() {
    if (window.XMLHttpRequest) {
        return new XMLHttpRequest();
    } else if (window.ActiveXObject) {
        return new ActiveXObject("Microsoft.XMLHTTP");
    }
    throw new Error("XMLHttp object could be created.");
}

function _sendRequest(url, func, isxml, postdata) {
    var xhr = createXMLHttp();
    if (!postdata) postdata = null;
    xhr.open(postdata ? "POST" : "GET", url, true);
    if (postdata) {
        xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
    }
    if (func) {
        xhr.onreadystatechange = function() {
            if (xhr.readyState == 4) {
                func(isxml && xhr.responseXML ? xhr.responseXML : xhr.responseText)
            }
        }
    }
    if (postdata === true) {
        postdata = '';
    }
    xhr.send(postdata)
}
function ajaxRead(file, fun) {
    var xmlObj = createXMLHttp();

    xmlObj.onreadystatechange = function() {
        if (xmlObj.readyState == 4) {
            if (xmlObj.status == 200) {
                obj = xmlObj.responseXML;
                eval(fun);
            }
            else {
                alert("读取文件出错,错误号为 [" + xmlObj.status + "]");
            }
        }
    }
    xmlObj.open('GET', file, true);
    xmlObj.send(null);
}

function getRequestBody(oForm) {
    var aParams = new Array();
    for (var i = 0; i < oForm.elements.length; i++) {
        /*
        if (oForm.elements[i].type == "checkbox" && oForm.elements[i].checked == false)
        {
        continue;
        }
        */
        var sParam = encodeURIComponent(oForm.elements[i].name);
        sParam += "=";
        sParam += encodeURIComponent(oForm.elements[i].value);
        aParams.push(sParam);
    }
    return aParams.join("&");
}


function getSpecificNodeValue(doc, tagname, index) {
    try {
        var oNodes = doc.getElementsByTagName(tagname);
        if (oNodes[index] != null && oNodes[index] != undefined) {
            if (oNodes[index].childNodes.length > 1) {
                return oNodes[index].childNodes[1].nodeValue;
            } else {
                return oNodes[index].firstChild.nodeValue;
            }
        }
    }
    catch (e) { }
    return '';
}

function getSingleNodeValue(doc, tagname) {
    try {
        var oNodes = doc.getElementsByTagName(tagname);
        if (oNodes[0] != null && oNodes[0] != undefined) {
            if (oNodes[0].childNodes.length > 1) {
                return oNodes[0].childNodes[1].nodeValue;
            } else {
                return oNodes[0].firstChild.nodeValue;
            }
        }
    }
    catch (e) { }
    return '';
}