第一种：<script language="javascript" type="text/javascript"> window.location.href="login.jsp?backurl="+window.location.href; </script>
第二种：<script language="javascript"> alert("返回"); window.history.back(-1);</script>
第三种：<script language="javascript"> window.navigate("top.jsp");</script>
第四种：<script language="JavaScript">self.location='top.htm';</script>
第五种：<script language="javascript">alert("非法访问！");top.location='xx.jsp';</script>
