众所周知window.open() 函数可以用来打开一个新窗口，那么如何在子窗体中向父窗体传值呢，其实通过window.opener即可获取父窗体的引用。
如我们新建窗体FatherPage.htm:
XML-Code:
<script type="text/javascript">function OpenChildWindow(){ window.open('ChildPage.htm'); }</script><input type="text" id="txtInput" /><input type="button" value="OpenChild" onclick="OpenChildWindow()" />
然后在ChildPage.htm中即可通过window.opener来访问父窗体中的元素：
XML-Code:
<script type="text/javascript">function SetValue(){ window.opener.document.getElementById('txtInput').value =document.getElementById('txtInput').value; window.close();}</script><input type="text" id="txtInput" /><input type="button" value="SetFather" onclick="SetValue()" />
其实在打开子窗体的同时，我们也可以对子窗体的元素进行赋值，因为window.open函数同样会返回一个子窗体的引用，因此FatherPage.htm可以修改为：
XML-Code:
<script type="text/javascript">function OpenChildWindow(){ var child = window.open('ChildPage.htm'); child.document.getElementById('txtInput').value =document.getElementById('txtInput').value; }</script><input type="text" id="txtInput" /><input type="button" value="OpenChild" onclick="OpenChildWindow()" />
通过判断子窗体的引用是否为空，我们还可以控制使其只能打开一个子窗体：
XML-Code:
<script type="text/javascript">var childfunction OpenChildWindow(){ if(!child) child = window.open('ChildPage.htm'); child.document.getElementById('txtInput').value =document.getElementById('txtInput').value; }</script><input type="text" id="txtInput" /><input type="button" value="OpenChild" onclick="OpenChildWindow()" />
光这样还不够，当关闭子窗体时还必须对父窗体的child变量进行清空，否则打开子窗体后再关闭就无法再重新打开了：
XML-Code:
<body onunload="Unload()"><script type="text/javascript">function SetValue(){ window.opener.document.getElementById('txtInput').value =document.getElementById('txtInput').value; window.close();}function Unload(){ window.opener.child=null;}</script><input type="text" id="txtInput" /><input type="button" value="SetFather" onclick="SetValue()" /></body>