Im trying to make a cube that executes different functions according with the face I´ve clicked, I just don´t know how to define wich one I´ve clicked, Any ideas?

Calculate the difference vector between the clicked position and the cubes center. Then you can examine which of the three components got the greatest absolute value and its sign.

Or try to use this to get a vector normal to the specific cube face:

vec_set(to,mouse_dir3d);
vec_scale(to,2000);
vec_add(to,mouse_pos3d);
c_trace(mouse_pos3d,to,USE_BOX | IGNORE_SPRITES | IGNORE_FLAG2);
vec_set(to,target.x);
vec_set(vec_normal,normal);

As Uhrwerk said, you can examine the greatest value with the normalvector from this code.

Uhrwerk: I get you, that was i tried to do, but i dont know how to especify the position i've clicked, if i use c_trace it returns the cube center
gameplan:thanks, but i'm not sure if i used that script correctly, but the result depends on my position and i need to be able to click any face from any position i.e. from some positions you can see tree faces of a cube and if im in that position i need to be able to click any of these faces

c_trace should return the distance to the hit entity, not a vector. Or were you talking about the hit vector?

yes i was talking of the hit vector

Now that is strange. Have you set USE_POLYGON? Did you try to create a particle at the hit vector's position in order to actually see where it is?

i had it dislabed before but even when it is, it place a sphere that i use as a mark weirdly, no matter where i click it place the sphere in the direction im looking each time closer to me

Ahhh now i get it, its because its going to put it at the "end" of the trace, i´ve solved it now

Ahhh now i get it, its because its going to put it at the "end" of the trace, i´ve solved it now