var xmlHttp;

function IsRepeat(Url, Par, ConID) {
   xmlHttp = GetXmlHttpObject();
    if (xmlHttp == null) {
        alert("您的浏览器不支持AJAX！");
        return;
    }
    if (Par != "")
        Url = Url + "?" + Par;
    xmlHttp.onreadystatechange = function() { stateChanged(ConID) };
    xmlHttp.open("post", Url, true);
    xmlHttp.send(null);
}

function stateChanged(ConID) {
    if (xmlHttp.readyState == 4) {
        document.getElementById(ConID).innerHTML = xmlHttp.responseText;
    }
}

function GetXmlHttpObject() {
    var xmlHttp = null;
    try {
        // Firefox, Opera 8.0+, Safari
        xmlHttp = new XMLHttpRequest();
    }
    catch (e) {
        // Internet Explorer
        try {
            xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
        }
        catch (e) {
            xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
    }
    return xmlHttp;
}