var Xml = {
    _req:null,
    _loadSafariXML: function(xml){
        var doc = null
        if (window.XMLHttpRequest) {
            this._req = new XMLHttpRequest();
            if (this._req.overrideMimeType) {
                this._req.overrideMimeType("text/xml");
            };
        }else if(window.ActiveXObject){
            try{
                this._req = new ActiveXObject('Msxml2.XMLHTTP');
            }catch(e){
                try{
                    this._req = new ActiveXObject('Microsoft.XMLHTTP');
                }catch(e){

                }
            }
        };
        this._req.onreadystatechange = function() {
            if (this._req.readyState == 4) {
                if (this._req.status == 200) {
                    doc = this._req.responseXML;
                }else{

                };
            };
        }.bind(this);
        this._req.open("GET",xml,false);
        this._req.send(null);
        return doc;
    },
    _loadFirefoxXML: function(xml_path) {
        var xmlDoc;
        if(window.ActiveXObject)
        {
            xmlDoc = new ActiveXObject('Microsoft.XMLDOM');
            xmlDoc.async = false;
            xmlDoc.load(xml_path);
        }
        else if (document.implementation&&document.implementation.createDocument)
        {
            xmlDoc = document.implementation.createDocument('', '', null);
            xmlDoc.async = false;
            xmlDoc.load(xml_path);
        }
        else
        {
            return null;
        }
        return xmlDoc;
    },
    load: function(xml_path) {
        var userAgent = navigator.userAgent; //取得浏览器的userAgent字符串
        var isOpera = userAgent.indexOf("Opera") > -1; //判断是否Opera
        var isMaxthon = userAgent.indexOf("Maxthon") > -1 ; //判断是否傲游3.0
        var isIE = userAgent.indexOf("compatible") > -1 && userAgent.indexOf("MSIE") > -1 && !isOpera ; //判断是否IE 
        var isFF = userAgent.indexOf("Firefox") > -1 ; //判断是否Firefox
        var isSafari = userAgent.indexOf("Safari") > -1 && userAgent.indexOf("Chrome") < 1 ; //判断是否Safari
        var isChrome = userAgent.indexOf("Chrome") > -1 ; //判断是否Chrome
        return (isSafari || isChrome) ? this._loadSafariXML(xml_path) : this._loadFirefoxXML(xml_path);
    },
    getNodeXml: function(node){
        if (!document.all) {
            var result = "";
            for(var i=0;i<node.childNodes.length;i++){
                if (node.childNodes[i].nodeType == 3) {result += node.childNodes[i].textContent};
                if (node.childNodes[i].nodeType == 1) {result += "<"+node.childNodes[i].tagName+">"+Xml.getNodeXml(node.childNodes[i])+"</"+node.childNodes[i].tagName+">"};
            }
            return result
        }else{
            var result = "";
            for(var i=0;i<node.childNodes.length;i++){
                if (node.childNodes[i].nodeType == 3) {result += node.childNodes[i].text};
                if (node.childNodes[i].nodeType == 1) {result += "<"+node.childNodes[i].tagName+">"+Xml.getNodeXml(node.childNodes[i])+"</"+node.childNodes[i].tagName+">"};
            }
            return result
        };
    }
}
// document.execCommand("BackgroundImageCache", false, true);



// 读取xml文档节点值
function getValue(tagName,root){//root为loadXML("url/url.xml")返回的结果
    var tags = root.getElementsByTagName(tagName);
	if (tags.length == 0){
		return [" "]
		}
    if (tags.length == 1) {
        return [tags[0].firstChild.nodeValue];
    }
    if (tags.length > 1) {
        var arr = new Array;
        for( var i=0; i < tags.length; i++){
            if (tags[i].firstChild) {
                arr.push(tags[i].firstChild.nodeValue);
            }
        }
        return arr;
    }
}