问当我试图在另一个Ajax-函数中调用Ajax-函数时，返回值=未定义。

EN

function getUserdataByToken() {

    var token = localStorage.getItem("token");
    var userDataRequest;

    //-AJAX-REQUEST
        var xhttp;
        if (window.XMLHttpRequest) {
            xhttp = new XMLHttpRequest();
        } else {
        // code for IE6, IE5
            xhttp = new ActiveXObject("Microsoft.XMLHTTP");
        }

        var url= window.location.protocol+"//"+window.location.host+"/getuserdatabytoken";
        var param = "token=" + token;

        xhttp.onreadystatechange = function() {
            if (xhttp.readyState == 4 && xhttp.status == 200) {
                userDataRequest = JSON.parse(xhttp.responseText);

                if (userDataRequest.success === "false") {
                    warningMessage('homeMessage', false, userDataRequest.message);
                } else {
                    return userDataRequest;
                }
            }
        };

        xhttp.open("POST", url, true);
        xhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
        xhttp.send(param);
}

    function sendPost(wall) {

        var content;
        var token = localStorage.getItem("token");
        var userData = getUserdataByToken(); // PROBLEM

        console.log(userData); // "leads to undefined"
        alert(userData); // "leads to undefined"
… Ajax Call etc…