The Problem is fixed with the help of a friend and it works fine with A7com!
You have to write into your mainscript:

SW_camera_Init();//Init the effect
PP_Toggle_OnOff();//Show the effect

into a included script you write:

////////////////////////////////////////// Monochrome////////////////////////////////////////////
material Monochrome_mat
{
effect = "monochrome.fx";
}

view SW_camera
{

}

entity PP_Quad
{
type = <PPE_Quad.tga>;
layer = 1;
view = camera;

x = 878;
y = 0;
z = 0;

scale_x = 1;
scale_y = 1;
flags=visible;
}

function PP_Init_startup()
{
SW_camera.bmap = bmap_for_entity(PP_Quad,0);
SW_camera.arc=60;
SW_camera.clip_far=100000;
}

function SW_camera_Init()
{
PP_Quad.material = Monochrome_mat;
}


function PP_Toggle_OnOff()
{
if(PP_Quad.visible == on)
{
SW_camera.visible = off;
PP_Quad.visible = off;
}else
{
SW_camera.visible = on;
PP_Quad.visible = on;

while(PP_Quad.visible == on)
{
vec_set(SW_camera.x,camera.x);
vec_set(SW_camera.pan,camera.pan);
wait(1);
}
}
}

on_t = PP_Toggle_OnOff;

For the "entity PP_Quad" you need a white tga-bitmap 1024*768!This Bitmap and the
monochrome.fx-file has to be in your gamefolder!
I think,other postprocessing-effects will also work with it,but I didn't test it until now.