<form action="" method="post" style="text-align: center ">
    <input type="text" name="email_1117" placeholder="请输入您的email(必填)" style="margin:1em;" id="winput_email">
    <input id="winput_email_check" style="border: 0 ;color: red;">
    <input type="submit" name="add" value="追加" id="w_submit">
</form>
<script>
    document.getElementById("winput_email").addEventListener("change", wonchange);
    function wonchange() {
        var w = document.getElementById("winput_email").value;
        var reg = /\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*/;
        console.log(reg.exec(w) !== null && reg.exec(w).index === 0)
        if (reg.exec(w) !== null && reg.exec(w).index === 0) {
            document.getElementById("winput_email_check").value = ‘‘
            document.getElementById("w_submit").style.display = ‘inline‘;
        } else {
            winnerhtml = ‘请输入正确的email‘;
            document.getElementById("winput_email_check").value = winnerhtml;
            document.getElementById("w_submit").style.display = ‘none‘;
        }
    }
</script>