nginx配置thinkphp的rewrite

以前web用apache的架设thinkphp的程序，但是转为nginx的服务器后，一直不能
正常网站，就是规则重写的问题；

apache的配置：
RewriteEngine On

RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f

RewriteRule ^(.*)$ index.php/$1 [QSA,PT,L]

RewriteRule ^/?([a-zA-Z0-9]+)$ index.php?app=home&mod=Public&act=error404 [L]

在Nginx的配置是这样的：
location / {
root /wwwroot/mysite;
index index.html index.htm index.php;
if (!-e $request_filename){
rewrite ^/(.*)$ /index.php/$1 last;
break;
}
}
location ~* .php$ {
root /wwwroot/mysite;
fastcgi_pass 127.0.0.1:9000;
fastcgi_index index.php;
include fastcgi.conf;

            set $real_script_name $fastcgi_script_name;
            if ($fastcgi_script_name ~ "^(.+?.php)(/.+)$"){
               set $real_script_name $1;
               set $path_info $2;
            }
            fastcgi_param  SCRIPT_FILENAME $document_root$real_script_name;
            fastcgi_param  SCRIPT_NAME  $real_script_name;
            fastcgi_param  PATH_INFO $path_info;
    }

看了网上很多有关解决的方案，都不生效，我的Nginx的版本1.4的；如有解答，不胜感激！！！