小编Joh*_*tog的帖子

我不知道这里出了什么问题。PreventDefault 应该阻止表单提交，但它仍然继续。我有一个 ajax 调用，它验证用户是否有效。如果没有，则阻止提交。否则，继续登录和主页。

形式

<form id="signIn" method="post" action="processForms.php">
    <table cellspacing="10">
        <tr id="errorSignIn" hidden="hidden">
            <td class="centerItem errorMessage" colspan="3">
                Incorrect Username and/or Password
            </td>
        </tr>
        <tr>
            <td><input type="text" id="username" name="username" autocomplete="off" autofocus required placeholder="Username..."></td>
            <td><input type="password" id="password" name="password" autocomplete="off" required placeholder="Password..."></td>
            <td><input type="submit" name="processButton" class="signIn" value="Sign-in" ></td>
        </tr>
    </table>
</form>

JavaScript

$('#signIn').submit ( function (e) {
    var username = $('#username').val();
    var password = $('#password').val();
    var dataString = "username=" + username + "&password=" + password;
    $.ajax( {
       type: "POST",
        url: "ajaxCheck.php",
        data: …