代码如下：
<SCRIPT LANGUAGE="JavaScript"> <!-- Begin netscape = (navigator.appName.indexOf("Netscape") != -1); version4 = (navigator.appVersion.indexOf("4.") != -1); if (netscape && version4) { ip = "" + java.net.InetAddress.getLocalHost().getHostAddress(); if (ip.indexOf("235.12") >= -1) // 这是想要禁止访问的IP例如: 235.12.xxx.xxx { alert("You are not permitted to access this site."); history.go(-1); } } // End --> </script>