<html><body>电子邮件：<input type="email" id="myEmail"><br><br><button onclick="disableBtn()">禁用电子邮件字段</button><button onclick="undisableBtn()">取消禁用电子邮件字段</button><script>function disableBtn() { document.getElementById("myEmail").disabled = true;}function undisableBtn() { document.getElementById("myEmail").disabled = false;}</script></body></html>