function getXMLHttp () {
    var xmlhttp;

    try {
        xmlhttp = new ActiveXObject ("Microsoft.XMLHTTP");
    } catch(e) {
        xmlhttp = new XMLHttpRequest();
    }
    return xmlhttp;
}

function sendParaStrRequest (url,params,func) {
    var xmlhttp = getXMLHttp();
    
    xmlhttp.onreadystatechange = function() {
        if (4==xmlhttp.readyState) {
            if (200==xmlhttp.status){
            var data = xmlhttp.responseText;
            func(data);
            }
            if (404==xmlhttp.status){
            }
        }
    };
    
    xmlhttp.open("post", url, true);
    xmlhttp.setRequestHeader('Content-type','application/x-www-form-urlencoded');
    xmlhttp.send(params);
}