regex - regular expressions on URL -

i need little assistants poor regex chops. trying grab 41398 url. number variable

http://www.website.com/beta/flips/index/41398_1363874140/friend/756

i figured out how grab / after index.

var url      = document.url; var myregexp = /index(.*)/; var match    = myregexp.exec(url);

this leaves me /41398_1363874140/friend/756....

is there solution regex grab number between / , _ ?

i tried

var url      = document.url; var myregexp = \/(.*?)\_; var match    = myregexp.exec(url);

and of course '/' issue.

if know there underscore can use:

var url      = document.url; var myregexp = /\d+_/; var match    = myregexp.exec(url);

Permission