获取网站跟路径的javascript代码(站点及虚拟目录)

代码如下:
<script>
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);
}
alert (getRootPath());
</script>