javascript 实现页面跳转的几种方式
    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>