javascript 擷取連結檔案地址中第一個斜線內的Regex_javascript技巧

window.location.pathname
比如：
/windows/location/page.html
我想得到“windows”，請問用Regex怎麼寫？

<script> var a="/windows/location/page.html"; var reg=/(^(http[s]?:\/\/[^\/]*\/)|(^\/))([^\/]+)\/.*$/ig; var t=a.replace(reg,"$4"); alert(a + "\n" + "\n" + t); var a=top.location + "/windows/location/page.html"; var t=a.replace(reg,"$4"); alert(a + "\n" + "\n" + t); alert(top.location + "\n" + "\n" + reg.test(top.location)); </script>
[Ctrl+A 全選 注:如需引入外部Js需重新整理才能執行]