javascript无提示关闭窗口，兼容IE,Firefox等。
实例代码：
<html><head><meta http-equiv="Content-Type" content="text/html; charset=gb2312"><title>无提关闭窗</title></head><body>
<script language="JavaScript" type="text/javascript">
function Close()
{
window.open('','_parent',''); window.close(); 
}</script><input type="button" value="关闭" onclick="Close();"/></body></html>