转载自: http://www.cnblogs.com/lgzslf/archive/2009/03/02/1401498.html
第一种:
<script language="javascript" type="text/javascript"> window.location.href="a.asp?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("a.asp"); </script>
第四种:
<script language="JavaScript"> self.location='a.asp'; </script>
第五种:
<script language="javascript"> alert("非法访问!"); top.location='a.asp'; </script>