和Danny关于Disabled=""的研究用例

<input type="checkbox"  id = "dd"><br>
<input type="checkbox"  id = "ee" disabled="true"><br>
<input type="checkbox"  id = "ff" disabled="disabled"><br>
<input type="submit" onclick="change()" value="change">
<script>
function change()
{
alert(document.getElementById("ee").disabled)
document.getElementById("ee").disabled=false
}
</script>
结论：即使checkbox有disabled="true"的属性，用JS也是可以改变它的页面上显的样子的(disabled = false)