How To Change The Sky Of Your Map

Summary
This tutorial will guide you through the simple process of changing the sky of your map.

Before we begin, let's take a look at where those custom sky files (.tga) should be located.
Location of the .tga files



(Valve\Steam\SteamApps\accountname\counter-strike\cstrike\gfx\env)
How to change the sky of your map
Now, as an example, let's say the following custom sky files were downloaded:



Whilst in Hammer, and after loading up your map, take a look at the top left of the screen, left click on Map, then left click on Map properties...:



In the Object Properties window, left click on environment map (cl_skyname):



In the environment map (cl_skyname) box, the following would have to be typed in order to active the custom sky:


Notice that the last two letters from the file names were missed out. No matter what the file names are, only the last two letters should be missed out.


Close the Object Properties window, compile your map, and marvel at your brand new sky (unless you've made a fully-indoor map or are just reading this tutorial to comment/assess it)! (:

Note: Remember to place all downloaded sky files into your cstrike\gfx\env folder, and also to include them in your .zip / .rar file before uploading your map for other people to download.
End
I hope you've found this tutorial helpful. Please let me know whether there's any spelling mistakes, issues, or general improvements I'm able to make to it via your comments.

Thank you and happy mapping!