i had these 2 lines:

VECTOR* temp;
temp.x = mouse_pos.x/100;

and they worked fine.
so i changed it to this:

VECTOR* temp;
temp.x =(mouse_pos.x/100)-4;

then the program crashes!
please help

what's your version?

Sure this is a big fat bug!

You need either a real vector, or a not empty pointer when you want to do something with it. Writing something into an empty pointer will of course crash.

its

VECTOR temp;

or

VECTOR* temp = { x=0; y=0; z=0; }

but not

VECTOR* temp;

that fixed the problem.
many thanks.