Clean urls - multiple joomla on same Nginx

[ryanpearl]

i have set up two joomlas on the same Nginx server
joomla1 on /html/
joomla2 on /html/joomla2

when i setup Clean urls on Nginx.conf

location / {
root /usr/local/nginx/html;
index index.php index.html index.htm;
try_files $uri $uri/ /index.php?$args;
}

problem come out:
at joomla2 ,the Clean urls fails, all lead to 404 page.
how can i config Nginx.conf? or how to support Clean urls on joomla2 . please advise. thanks dude.