Problem! Trying to launch the server on Mac.

I'm fairly new to all of this, but I'm following the guide to start it on a mac. Everything works pretty well, but when I try to save the TextEdit file,
(Obtaining startup script
To easily start the server you will need a startup script. The following is a basic server script to start your server.

1. Open up TextEdit and paste the following in
   #!/bin/bash
   cd "$( dirname "$0" )"
   java -Xmx1024M -Xms1024M -jar craftbukkit.jar
2. Save the file
   Save it in your CraftBukkit folder as start_server.command)
   
   Okay. Not a big deal, but I can't save it with .command. It gives me an option to change it to .rtf (I think...) or to use both .rtf AND .command. I use that option and delete the .rtf part of it. Now it turns into a terminal run script which looks right to me. However, when I try to run it I get an error pop-up that says, "The file “start_server.command” could not be executed because you do not have appropriate access privileges.
   To view or change access privileges, select the file in the Finder and choose File > Get Info."
   Thats the second problem, I don't know what I'm looking for once I get there.
   Help a technology newb out here please?​