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>