opener.document.PostTopic.Message.value

打开子窗口的父窗口的PostTopic集合Message的值

模拟一下：
index.htm
=========
<form name="PostTopic">
<input type="text" name="Message" value="www">
</form>
<input type="button" value="确定" onclick="window.open('1.htm')">

================================
1.htm
=======
<input type="button" value="yes" onclick="alert(opener.document.PostTopic.Message.value)">

打开表单PostTopic的Message单元的值