multi account site - htaccess question

Hey there, i am trying to make a little app that will serve multiple accounts, each one with it's user, etc.

so basically i got:

RewriteEngine on

RewriteBase /


RewriteRule ^$                        index.php  [L]
RewriteCond %{REQUEST_FILENAME}       !-f
RewriteCond %{REQUEST_FILENAME}       !-d


RewriteRule (.*)/(.*)/(.*)$                       index.php?account=$1&task=$2&id=$3

this works fine for http://sd.domain.com/a开发者_如何学Pythonccountname/index/

but not for: http://sd.domain.com/accountname, is throwing a 404.

so i think i need to just use the variables only when there are present, so i can make something like:

http://sd.domain.com/accountname -- default index controller --

http://sd.domain.com/accountname/index

http://sd.domain.com/accountname/campaigns/

http://sd.domain.com/accountname/view_campaign/5 -- campaign id should be here --

Thanks in advance, hope anyone can help.

Try this.

RewriteRule ^([^/]+)/?([^/]*)/?([^/]*)$ index.php?account=$1&task=$2&id=$3