var xmlHttp;
var methord;
//调用此方法返回xml数据
function getXMLHttpRequest(url) {
    if (window.ActiveXObject) {
        xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
        methord = "post";
    }
    else if (window.XMLHttpRequest) {
        xmlHttp = new XMLHttpRequest();
        methord = "get";
    }
    xmlHttp.onreadystatechange = XmlOnReadyStateChange;
    xmlHttp.open(methord, url, false);
    xmlHttp.send(null);
    return XmlOnReadyStateChange();
}
//调用此方法返回text
function getTextHttpRequest(url) {
    if (window.ActiveXObject) {
        xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
        methord = "post";
    }
    else if (window.XMLHttpRequest) {
        xmlHttp = new XMLHttpRequest();
        methord = "get";
    }
    xmlHttp.onreadystatechange = TextOnReadyStateChange;
    xmlHttp.open(methord, url, false);
    xmlHttp.send(null);
    return TextOnReadyStateChange();
}
//返回为text
function TextOnReadyStateChange() {
    var code;
    if (xmlHttp.readyState == 4) {
        if (xmlHttp.status == 200) {
            code = xmlHttp.responseText;
        }
    }
    return code;
}
//返回xml数据
function XmlOnReadyStateChange() {
    var code;
    if (xmlHttp.readyState == 4) {
        if (xmlHttp.status == 200) {
            code = xmlHttp.responseXml;
        }
    }
    return code;
}
String.prototype.trim = function() {
    // 用正则表达式将前后空格，用空字符串替代。
    return this.replace(/(^\s*)|(\s*$)/g, "");
}