Gmod Dedicated Server Problem

I have recently made a Dedicated Server on gmod…It works fine but the only thing i need help is that it won’t allow me to spawn CSS,DOD,Portal and all other props except HL2…I have the games i need for the props but it just won’t let me spawn…I even tried to use a CSS gun and still nothing i can’t even spawn jalopy…

Any ideas how i can mount those contents in the server?
It’s confusing…

Also i have them mounted on GMOD but…

http://img819.imageshack.us/img819/2936/steamdedicatedserver.png

Oh now i checked console and it says this

It says on CSS,HL2 EP2 Fail…Any ideas?

You need to install the content.