关闭窗口的问题！

在IE中，现有窗口A，然后A打开一个新窗口B，在窗口C中把窗口B关闭掉page_a:
<html>
<body>
page A:<br/>
<input type="button" value="Open B" onClick="window.open('page_b.htm','page_b','width=600,height=400');">
</body>
</html>
---------------------------------------------------------------
page_b:
<html>
<body>
page_b:<br/>
<input type="button" value="window B" onClick="window.opener.close();">
</body>
</html>
---------------------------------------------------------------
page_c:
<html>
<body>
page_c:<br/>
<input type="button" value="Close B" onClick="window.open('page_b.htm','page_b','width=600,height=400').close();">
</body>
</html>