<script>
		function calculateAge() {
			let birthday = new Date(document.getElementById("birthday").value);
			let today = new Date();
			let age = today.getFullYear() - birthday.getFullYear();
			let m = today.getMonth() - birthday.getMonth();
			if (m < 0 || (m === 0 && today.getDate() < birthday.getDate())) {
				age--;
			}
			document.getElementById("result").innerHTML = "당신의 만 나이는 " + age + "세 입니다.";
		}
	</script>