i can't access my subdomain on localhost.
my localdomain is localhost.dev and it's work.but i want to auto subdomain for php script (username.localhost.dev)
i try this

server { listen 80 default_server; listen [::]:80 default_server ipv6only=on; access_log /var/www/access.log; error_log /var/www/error.log; root /var/www; index index.php index.html index.htm;

# Make site accessible from http://localhost/
server_name localhost.dev ***.localhost.dev**;

location / {
    # First attempt to serve request as file, then
    # as directory, then fall back to displaying a 404.
    try_files $uri $uri/ /index.html;
    # Uncomment to enable naxsi on this location
    # include /etc/nginx/naxsi.rules
}

location /f2/public/ {

 try_files $uri $uri/ /f2/public/index.php?$args;
    }
location /doc/ {
    alias /usr/share/doc/;
    autoindex on;
    allow 127.0.0.1;
    allow ::1;
    deny all;
}

# Only for nginx-naxsi used with nginx-naxsi-ui : process denied requests
#location /RequestDenied {
#   proxy_pass http://127.0.0.1:8080;    
#}

#error_page 404 /404.html;

# redirect server error pages to the static page /50x.html
#
#error_page 500 502 503 504 /50x.html;
#location = /50x.html {
#   root /usr/share/nginx/html;
#}

# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
#
location ~ \.php$ {
#   fastcgi_split_path_info ^(.+\.php)(/.+)$;
#   # NOTE: You should have "cgi.fix_pathinfo = 0;" in php.ini
#
#   # With php5-cgi alone:
#   fastcgi_pass 127.0.0.1:9000;
#   # With php5-fpm:
#   fastcgi_pass unix:/var/run/php5-fpm.sock;
#   fastcgi_index index.php;
#   include fastcgi_params;
include /etc/nginx/fastcgi_params;
    try_files     $uri =404;
    fastcgi_pass  127.0.0.1:9000;
    fastcgi_index index.php;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;   
}

# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
#location ~ /\.ht {
#   deny all;
#}
   }

it's not working.i change server_name for testing
server_name localhost.dev asd.localhost.dev;
i can't access asd.localhost.dev
and i try this double server{} section

# You may add here your
# server {
#   ...
# }
# statements for each of your virtual hosts to this file

##
# You should look at the following URL's in order to grasp a solid understanding
# of Nginx configuration files in order to fully unleash the power of Nginx.
# http://wiki.nginx.org/Pitfalls
# http://wiki.nginx.org/QuickStart
# http://wiki.nginx.org/Configuration
#
# Generally, you will want to move this file somewhere, and start with a clean
# file but keep this around for reference. Or just disable in sites-enabled.
#
# Please see /usr/share/doc/nginx-doc/examples/ for more detailed examples.
##

server {
    listen 80 default_server;
    listen [::]:80 default_server ipv6only=on;
    access_log /var/www/access.log;
        error_log /var/www/error.log;
    root /var/www;
    index index.php index.html index.htm;

    # Make site accessible from http://localhost/
    server_name localhost.dev;

    location / {
        # First attempt to serve request as file, then
        # as directory, then fall back to displaying a 404.
        try_files $uri $uri/ /index.html;
        # Uncomment to enable naxsi on this location
        # include /etc/nginx/naxsi.rules
    }

    location /f2/public/ {

     try_files $uri $uri/ /f2/public/index.php?$args;
        }
    location /doc/ {
        alias /usr/share/doc/;
        autoindex on;
        allow 127.0.0.1;
        allow ::1;
        deny all;
    }

    # Only for nginx-naxsi used with nginx-naxsi-ui : process denied requests
    #location /RequestDenied {
    #   proxy_pass http://127.0.0.1:8080;    
    #}

    #error_page 404 /404.html;

    # redirect server error pages to the static page /50x.html
    #
    #error_page 500 502 503 504 /50x.html;
    #location = /50x.html {
    #   root /usr/share/nginx/html;
    #}

    # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
    #
    location ~ \.php$ {
    #   fastcgi_split_path_info ^(.+\.php)(/.+)$;
    #   # NOTE: You should have "cgi.fix_pathinfo = 0;" in php.ini
    #
    #   # With php5-cgi alone:
    #   fastcgi_pass 127.0.0.1:9000;
    #   # With php5-fpm:
    #   fastcgi_pass unix:/var/run/php5-fpm.sock;
    #   fastcgi_index index.php;
    #   include fastcgi_params;
    include /etc/nginx/fastcgi_params;
        try_files     $uri =404;
        fastcgi_pass  127.0.0.1:9000;
        fastcgi_index index.php;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;   
    }

    # deny access to .htaccess files, if Apache's document root
    # concurs with nginx's one
    #
    #location ~ /\.ht {
    #   deny all;
    #}
}
###############################
server {
access_log /var/www/access.log;
        error_log /var/www/error.log;
    root /var/www;
    index index.php index.html index.htm;

    # Make site accessible from http://localhost/
    server_name asd.localhost.dev;

    location / {
        # First attempt to serve request as file, then
        # as directory, then fall back to displaying a 404.
        try_files $uri $uri/ /index.html;
        # Uncomment to enable naxsi on this location
        # include /etc/nginx/naxsi.rules
    }

    location /f2/public/ {

     try_files $uri $uri/ /f2/public/index.php?$args;
        }
    location /doc/ {
        alias /usr/share/doc/;
        autoindex on;
        allow 127.0.0.1;
        allow ::1;
        deny all;
    }

    # Only for nginx-naxsi used with nginx-naxsi-ui : process denied requests
    #location /RequestDenied {
    #   proxy_pass http://127.0.0.1:8080;    
    #}

    #error_page 404 /404.html;

    # redirect server error pages to the static page /50x.html
    #
    #error_page 500 502 503 504 /50x.html;
    #location = /50x.html {
    #   root /usr/share/nginx/html;
    #}

    # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
    #
    location ~ \.php$ {
    #   fastcgi_split_path_info ^(.+\.php)(/.+)$;
    #   # NOTE: You should have "cgi.fix_pathinfo = 0;" in php.ini
    #
    #   # With php5-cgi alone:
    #   fastcgi_pass 127.0.0.1:9000;
    #   # With php5-fpm:
    #   fastcgi_pass unix:/var/run/php5-fpm.sock;
    #   fastcgi_index index.php;
    #   include fastcgi_params;
    include /etc/nginx/fastcgi_params;
        try_files     $uri =404;
        fastcgi_pass  127.0.0.1:9000;
        fastcgi_index index.php;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;   
    }

    # deny access to .htaccess files, if Apache's document root
    # concurs with nginx's one
    #
    #location ~ /\.ht {
    #   deny all;
    #}
}

# another virtual host using mix of IP-, name-, and port-based configuration
#
#server {
#   listen 8000;
#   listen somename:8080;
#   server_name somename alias another.alias;
#   root html;
#   index index.html index.htm;
#
#   location / {
#       try_files $uri $uri/ =404;
#   }
#}


# HTTPS server
#
#server {
#   listen 443;
#   server_name localhost;
#
#   root html;
#   index index.html index.htm;
#
#   ssl on;
#   ssl_certificate cert.pem;
#   ssl_certificate_key cert.key;
#
#   ssl_session_timeout 5m;
#
#   ssl_protocols SSLv3 TLSv1;
#   ssl_ciphers ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv3:+EXP;
#   ssl_prefer_server_ciphers on;
#
#   location / {
#       try_files $uri $uri/ =404;
#   }
#}

i can't success