//ajax功能
var http_request = null;
function getXmlActiveXobject(method, reqData, responsefunction) {
    if (http_request == null) {
        if (window.XMLHttpRequest) {
               // 创建 Mozilla/FireFox平台的 XMLHttpRequest 对象
            http_request = new XMLHttpRequest();
            if (http_request.overrideMimeType) {//设置MiME 类别
                http_request.overrideMimeType("text/xml");
            }
        } else {
            if (window.ActiveXObject) { 
               // 创建 IE/Windows 平台的XMLHttp对象
                http_request = new ActiveXObject("Msxml2.XMLHTTP");
            }
        }
        if (http_request == null) {
            http_request = new ActiveXObject("Microsoft.XMLHTTP");
        }
    }
    if (responsefunction) {
        http_request.open("GET", "ajaxAction.action?ajaxType=" + method + "&" + reqData, true);
        http_request.onreadystatechange = responsefunction;
    } else {
        http_request.open("GET", "ajaxAction.action?ajaxType=" + method + "&" + reqData, false);
    } 
    http_request.send(null);
    return http_request;
}
  
 // 返回xml
function loadXMLDoc(method, reqData, responsefunction) {
    try {
        var http_request = getXmlActiveXobject(method, reqData, responsefunction);
        if (responsefunction) {//异步
            return;
        } else {
            return http_request.responseXML;
        }
    }
    catch (exception) {
        alert(exception);
    }
}

// 返回text
function loadTextDoc(method, reqData, responsefunction) {
    try {
        var http_request = getXmlActiveXobject(method, reqData, responsefunction);
        if (responsefunction) {//异步
            return;
        } else {
        }
        return http_request.responseText;
    }
    catch (exception) {
        alert(exception);
    }
}