I am running the command rails server on ubuntu 12.04 having rails 3 but getting following error.
amir@ubuntu:~/app$ rails server /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/execjs-1.4.0/lib/execjs/runtimes.rb:51:in `autodetect': Could not find a JavaScript runtime. See https://github.com/sstephenson/execjs for a list of available runtimes. (ExecJS::RuntimeUnavailable) from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/execjs-1.4.0/lib/execjs.rb:5:in `<module:ExecJS>' from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/execjs-1.4.0/lib/execjs.rb:4:in `<top (required)>' from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/coffee-script-2.2.0/lib/coffee_script.rb:1:in `require' from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/coffee-script-2.2.0/lib/coffee_script.rb:1:in `<top (required)>' from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/coffee-script-2.2.0/lib/coffee-script.rb:1:in `require' from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/coffee-script-2.2.0/lib/coffee-script.rb:1:in `<top (required)>' from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/coffee-rails-3.2.2/lib/coffee-rails.rb:1:in `require' from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/coffee-rails-3.2.2/lib/coffee-rails.rb:1:in `<top (required)>' from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/bundler-1.1.4/lib/bundler/runtime.rb:68:in `require' from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/bundler-1.1.4/lib/bundler/runtime.rb:68:in `block (2 levels) in require' from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/bundler-1.1.4/lib/bundler/runtime.rb:66:in `each' from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/bundler-1.1.4/lib/bundler/runtime.rb:66:in `block in require' from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/bundler-1.1.4/lib/bundler/runtime.rb:55:in `each' from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/bundler-1.1.4/lib/bundler/runtime.rb:55:in `require' from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/bundler-1.1.4/lib/bundler.rb:119:in `require' from /home/amir/app/config/application.rb:7:in `<top (required)>' from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/railties-3.2.6/lib/rails/commands.rb:53:in `require' from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/railties-3.2.6/lib/rails/commands.rb:53:in `block in <top (required)>' from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/railties-3.2.6/lib/rails/commands.rb:50:in `tap' from /home/amir/.rvm/gems/ruby-1.9.2-p320/gems/railties-3.2.6/lib/rails/commands.rb:50:in `<top (required)>' from script/rails:6:in `require' from script/rails:6:in `<main>'
Any help is appreciable.
Thanks Amir