表单验证

<form action="" class="am-form">
    <fieldset>
        <legend>H5 原生表单验证</legend><br>
        <div class="am-form-group">
            <label for="doc-vld-name">用户名：</label><br><br>
            <input type="text" id="doc-vld-name" minlength="3" placeholder="输入用户名" class="am-form-field" required/><br><br>
            <label for="doc-vld-name">邮箱：</label><br><br>
            <input type="email" id="doc-vld-name" minlength="3" placeholder="输入用户名" class="am-form-field" required/><br><br>
            <label for="doc-vld-name">网址：</label><br><br>
            <input type="url" id="doc-vld-name" minlength="3" placeholder="输入用户名" class="am-form-field" required/><br><br>
            <label for="doc-vld-name">年龄：</label><br><br>
            <input type="age" id="doc-vld-name" minlength="3" placeholder="输入用户名" class="am-form-field" required/><br><br>
            <label for="doc-vld-name">评论：</label><br><br>
            <input type="pinglun" id="doc-vld-name" minlength="3" placeholder="输入用户名" class="am-form-field" required/><br><br>
        </div>
        <input type="submit">
    </fieldset>
</form>