After you created the toon.fx you have to #include it into your project,and because it is an post-process shader i think you want to add it to your camera, so you have to add the following to your main function
function main()
{
pp_set(camera,Toon_mat);
....
}
I´m not an expert in this Task but for me it works.

It´s late and i have to work tomorrow so I´m away.Play around a little bit.Will look for this thread tomorrow.