<p><a href="<?php echo base_url();?>usercenter/index" id="message"></a> </p> 

<script type="text/javascript">

var time = 0;

var forward_url ="<?php echo base_url();?>usercenter/index";//某页网址

function forward_to(){

     time ++;

     if(time == 5){

         document.location.href = forward_url;

     }

     document.getElementById("message").innerHTML = (5-time) + "秒后自动跳转到某页";

}

window.setInterval("forward_to()",1000);

</script>