[Closed] How to use snapmode in mousetrack function on defined objects

Hi. I use 3ds max 2014. I want to make autogrid function. But i have a problem. I cant use snapmode in mousetrack function.
if i write start command(mouseTrack trackCallback:mousetrackfn on:all) without “on:all”, snapmode can be usable. But this time i cant use ir.dir command over any objects

this is my code. thank you all.

(
all = geometry as array

fn mousetrackfn msg ir obj faceNum shift ctrl alt =
(
if msg == #freeMove do
(
if ir == undefined do return #continue
print ir.dir
return #continue
)
)
mouseTrack trackCallback:mousetrackfn on:all
)