Redmine

I'm trying to start redmine, when i open

localhost/redmine

browser loads error page:

晓腾 沈 on Rails application could not be started
Error message:
No such file or directory - config/environment.rb
Exception class:
Errno::ENOENT
Application root:
/var/www

Backtrace:# File Line Location
0 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/utils.rb 676 in `lstat'
1 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/utils.rb 676 in `lower_privilege'
2 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/utils.rb 198 in `prepare_app_process'
3 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/classic_rails/application_spawner.rb 176 in `initialize_server'
4 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/utils.rb 564 in `report_app_init_status'
5 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/classic_rails/application_spawner.rb 174 in `initialize_server'
6 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/abstract_server.rb 204 in `start_synchronously'
7 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/abstract_server.rb 180 in `start'
8 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/classic_rails/application_spawner.rb 149 in `start'
9 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/spawn_manager.rb 219 in `spawn_rails_application'
10 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/abstract_server_collection.rb 132 in `lookup_or_add'
11 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/spawn_manager.rb 214 in `spawn_rails_application'
12 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/abstract_server_collection.rb 82 in `synchronize'
13 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/abstract_server_collection.rb 79 in `synchronize'
14 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/spawn_manager.rb 213 in `spawn_rails_application'
15 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/spawn_manager.rb 132 in `spawn_application'
16 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/spawn_manager.rb 275 in `handle_spawn_application'
17 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/abstract_server.rb 357 in `__send__'
18 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/abstract_server.rb 357 in `server_main_loop'
19 /var/lib/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/abstract_server.rb 206 in `start_synchronously'
20 /var/lib/gems/1.8/gems/passenger-3.0.2/helper-scripts/passenger-spawn-server@

environment.rb is present and i give it chmod 777 and still nothing

what i have to do?