//js获取网站根路径(站点及虚拟目录)，获得网站的根目录或虚拟目录的根地址     
    function getRootPath(){
        var strFullPath=window.document.location.href;
        var strPath=window.document.location.pathname;
        var pos=strFullPath.indexOf(strPath);
        var prePath=strFullPath.substring(0,pos);
        var postPath=strPath.substring(0,strPath.substr(1).indexOf('/')+1);
        return(prePath+postPath);
   }

//在thinkPHP中用稍加修改

<script type='text/javascript'>
function getRootPath(){
       var strFullPath=window.document.location.href; 
       var pos=strFullPath.lastIndexOf('/');
       var prePath=strFullPath.substring(0,pos);
       return(prePath+'/info?code=".$code."');
}
str=getRootPath();
window.location=str;
</script>