Problem converting shader

Hi, i'm trying to put a Fur shader in my animation, but 3dgs gives me an error in this lines:

const half4x4 matWorldViewProj; ------ keyword unknown 'const'
const half4x4 matWorld; ------ keyword unknown 'const'
const half4x4 matWorldIT; ------ keyword unknown 'const'

And with the rest of the lines of the script :S
This is a HLSL script, so why this errors?

as far as I know GS HLSL doesn't support the const variable type, you might want to try

float4x4 matWorldViewProj;

Its doesnt work yet... GS now send me another error messages in another lines :S
but thnks for the hint

Is there a site where i can download some shader specially made for GS so i cant see how they'r made?

http://www.coniserver.net/wiki/index.php

Thanks a lot