Question

js readonly 怎么控制输入框内的可读不可读，想让一个不可读输入框中的内容在点击相应按钮的情况下改为可

function doclick1(){
alert('123')
var txtN = document.getElementById("contactus5");
txtN.setAttribute("readonly",true ,0);
}
<input type="text" id="contactus5" readonly>
<input type="button" name="button4" value="修改" onclick="doclick1();" />

Answer 1

这样：
<script>function doclick1(){

var txtN = document.getElementById("contactus5");
txtN.readOnly = false;
}
</script>
<input type="text" id="contactus5" readonly>
<input type="button" name="button4" value="修改" onclick="doclick1();" />