<!DOCTYPE html>
<html lang="ko">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>event_login</title>
<script src="https://code.jquery.com/jquery-3.6.1.min.js"></script>
<script>
$(function () {
$("#user_id").focus();
let id = "black";
let userId;
$("#user_id").change(function () {
userId = $("#user_id").val();
if (id == userId) {
$(".btn").click(function () {
alert(userId + "님 방문을 환영합니다.");
});
} else {
alert("정보가 없는 회원입니다.");
}
});
});
</script>
</head>
<body>
<b>ID</b>
<input type="text" id="user_id" />
<button class="btn">로그인</button>
</body>
</html>