Problem loading shaders

[Cryatal]

I have spent all day trying to implement the sepia tone shader from http://www.moddb.com/games/half-life-2/ ... ess-shader

I know its a bit out dated but iv finally got everything to compile without errors. However, when I type in the console command to activate sepia my screen goes white and I get the following errors in the console:

Binding uncached material "shaders/post_sepia", artificially incrementing refcount
Couldn't load pixel shader post_sepia_ps20
Couldn't load vertex shader post_screenspaceeffect_vs20

[[Steve]]

i would also like to know how to do this, as i could never get it working either