前端通過ajax提交from表單

<form id="signupForm">
    <h3 class="text-center">用戶登錄</h3>
    <p class="m-t-md text-center">歡迎登錄</p>
    <input id="username" type="text" name="username" class="form-control uname" placeholder="請輸入電話號碼"/>
    <!--  th:value="${username}" -->
    <input id="password" type="password" name="password" class="form-control pword m-b"
           placeholder="請輸入電話號碼"/>
    <input id="login" type="button" onclick="loginUser()" value="登錄" class="btn btn-login btn-block"/>
    <div class="row">
        <div class="col-xs-6 pull_left">
            <div class="form-group">
                <input class="form-control" type="tel" name="verify" id="verify" placeholder="請輸入驗證碼"maxlength="4">
            </div>
        </div>
        <div class="col-xs-6 pull_left">
            <a href="javascript:void(0);" rel="external nofollow" title="點擊更換驗證碼">
                <img style="margin-top: 12px;" id="imgVerify" src="" alt="更換驗證碼" height="36" width="100%" onclick="getVerify(this);">
            </a>
        </div>
    </div>
    <div id="msg" class="info_msg"></div>
</form>
<script type="text/javascript">
    $("#imgVerify").click();
    function loginUser() {
        validateRule();
        $("body").keydown(keyDownLogon);
        var fromData = {
            "username": $("#username").val(),
            "password": $("#password").val(),
            "verify": $("#verify").val()
        };
        $.ajax({
            type: "POST",
            url: "/login",
            data: fromData,
            success: function (r) {
                console.log("dasf")
                if (r.code === 0) {
                   window.location.href = "/user/index";                   
                } else {
                    document.getElementById("msg").innerHTML = r.msg;
                }
            },
        });
    }

    function keyDownLogon() {
        if (event.keyCode === "13") {
            $("#login").trigger('click');
        }
    }


    function validateRule() {
        var icon = "<i class='fa fa-times-circle'></i> ";
        $("#signupForm").validate({
            rules: {
                username: {
                    required: true
                },
                password: {
                    required: true
                },
                verify: {
                    required: true
                }
            },
            messages: {
                username: {
                    required: icon + "請輸入您的賬號",
                },
                password: {
                    required: icon + "請輸入您的密碼",
                },
                verify: {
                    required: icon + "請輸入驗證碼",
                }
            }
        })
    }

    //獲取驗證碼
    function getVerify(obj) {
        obj.src = "/getVerify?" + Math.random();
    }

效果如下圖