1
<form id="form1">2
<button id="button1" type="button">点我!</button>3
</form>4
<p>含有按钮的表单的ID:5
<script>6
document.write(document.getElementById("button1").form.id);7
</script>8
</p>
<form id="form1"> <button id="button1" type="button">点我!</button></form><p>含有按钮的表单的ID: <script> document.write(document.getElementById("button1").form.id); </script></p>