textures/yourmap/sky
{
qer_editorimage textures/skies/sky.tga
surfaceparm sky
surfaceparm noimpact
surfaceparm nomarks
q3map_nolightmap
skyParms textures/yourmap/sky x -
}


(Line 1, you replace "yourmap" with the name of your textures folder the skybox images are in
replace "sky" with the name of the sky, if you have the images named like, "mpo_ft.jpg",
then replace "sky" with "mpo".

Line 7, you replace "yourmap" again with the same path as you put in line 1, and do the same
for "sky", you must replace x with the dimensions of the image, if the images are 512x512, 
replace x with 512, if the images are 1024x1024, replace x with 1024.)

You need to make this file into a .shader file, just rename the file you copy this into
from mysky.txt to mysky.shader.  Open .shader files with notepad.  Give your shader the
same name as your map.  Then put it into your shaders folder, inside the base folder
in which all pk3 files go.  when you put the shader in the shader folder, open shaderlist.txt
and add your shader's name to the list, it must be in alphabetical order, and you must
copy and paste the symbols before and after all the names already in the file so they seperate
your shaders name from the others.