获取或转换XML对象，从string和URL中获取

businessObj.loadXMLString = function(xmlString, callback, parameter){
    var xml = new ActiveXObject("Microsoft.XMLDOM");
    xml.onreadystatechange=xmlRead;
    xml.async = false;
    function xmlRead(){
        if (xml.readyState == 4){
            if (callback){
                if (parameter){
                    callback.apply(xml,parameter);
                }else{
                    callback.apply(xml);
                }
            }
        }
    }
    xml.loadXML(xmlString);
    return xml;
}

/**
    读取XML的方法async = false
    xmlURL-文件的URL
**/
businessObj.loadXML = function(xmlURL, callback, parameter){
    var xml = new ActiveXObject("Microsoft.XMLDOM");
    xml.onreadystatechange=xmlRead;
    xml.async = false;
    function xmlRead(){
        if (xml.readyState == 4){
            if (callback){
                if (parameter){
                    callback.apply(xml,parameter);
                }else{
                    callback.apply(xml);
                }
            }
        }
    }
    xml.load(xmlURL);
    return xml;
}