父页面通过window.open打开的子页面
father.html
<input type="" name="main" id="mmm" value="123" />
<script type="text/javascript">
$('#Btn').on('click',function(){
window.open('son.html');
});
</script>
son.html
<script type="text/javascript">
alert(window.opener.document.getElementById('mmm').value);
</script>
控制台
Uncaught TypeError: Cannot read property 'value' of null at son.html:21
什么环境下试的,域名是可用的吧