<!DOCTYPE html>
<html>
<body>
<form>
姓:<input id="fname"><br>
名:<input id="lname"><br>
</form>
<p>点击按钮禁用第一个文本域。</p>
<button onclick="disableElement()">禁用文本域</button>
<script>
function disableElement()
{
document.getElementById("fname").disabled=true;
}
</script>
</body>
</html>
