Error while starting rails over "ruby script/server"

I am very new to Ruby on Rails, but also very excited to get those
things started.
I downloaded and installed “BitNami RubyStack Stack 1.4-beta-1” which
includes all necessary tools for running RoR offline under OS X (10.5).
I tried to get it started before in some other different ways, but I
never got it, because I am very new to this.
Finally now I tried to start my rails app, but then something strange
happened.

In my web browser should http://localhost:3000 open my active rails
application, but there’s only following error message:

Status: 500 Internal Server Error Content-Type: text/html
Application error (Rails)

So I tried to start the rails app over the Terminal. I changed to my
railsapp-folder and entered: “ruby script/server” which should start
Mongrel for my railsapp.

But the Terminal showed me:

=> Booting Mongrel (use ‘script/server webrick’ to force WEBrick)
=> Rails 2.2.2 application starting on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
** Starting Mongrel listening at 0.0.0.0:3000
Exiting
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel/tcphack.rb:12:in
initialize_without_backlog': Address already in use - bind(2) (Errno::EADDRINUSE) from /Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel/tcphack.rb:12:in initialize’
from
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:93:in new' from /Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:93:in initialize’
from
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel/configurator.rb:139:in
new' from /Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel/configurator.rb:139:in listener’
from
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/bin/mongrel_rails:99:in
cloaker_' from /Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel/configurator.rb:50:in call’
from
/Library/Ruby/Gems/1.8/gems/mongrel-1.1.5/lib/mongrel/configurator.rb:50:in
initialize' ... 14 levels... from /Library/Ruby/Gems/1.8/gems/rails-2.2.2/lib/commands/server.rb:49 from /Library/Ruby/Site/1.8/rubygems/custom_require.rb:31:in gem_original_require’
from /Library/Ruby/Site/1.8/rubygems/custom_require.rb:31:in
`require’
from script/server:3

It says, that the localhost-address is already in use, but I have no
idea how I can reset it.
Can somebody help me with this problem?

Greetz,
Marcel

It says, that the localhost-address is already in use, but I have no
idea how I can reset it.
Can somebody help me with this problem?

Greetz,
Marcel

Marcel,

This may help you

open terminal

type ps ax

toward the bottom of what it spits out it there will be something like:

482 p1 S+ 0:16.45 ruby script/server

type kill and then the first number ( in this case it was 482 )

like this:

kill 482

Then try and restart using ruby script/server command from your
terminal.