zoom in and out using middle mouse

whats the script codes for using the middle mouse roll forward and backward in order to zoom in and out the map ?
thx.

adjusting the camera.arc would do the zoom in/out.
try to look in the manual for mouse_middle

Try to use the manual it is a big help...

mickey
Movement of the mouse in pixels (mickey.x, mickey.y) and the mouse wheel in 120 units per notch (mickey.z) within the last frame.
Type:
vector, read-only
Example:
action move_me_by_mouse()
{
mouse_mode = 0;
while (1)
{
my.pan += mickey.x*time_step;
my.tilt += mickey.y*time_step;
c_move(me,vector(mickey.z*0.1*time_step,0,0),nullvector,0);
wait(1);
}
}