why does the timer not work ???

try (DestroyDialog Dist) catch()
rollout Dist "Dist" width:90 height:50
(
	local CamPar = $PhysCamera001.clip_near
	checkbutton cbn_Plus "+" checked:false tooltip:"Far from Camera"
	timer MC "P" interval:1000 active:false
 
	on Dist open do
	(
		$PhysCamera001.clip_on = true
	)
 
	on cbn_Plus changed theState do
	(
		if ( cbn_Plus.checked == true ) then
		(
			MC.active = true
		)
		else
		(
			MC.active = false
		)
	)
 
	on MC tick do
	(
-- 		CamPar += 1
		$PhysCamera001.clip_near += 1
		format "nc: % \n" $PhysCamera001.clip_near
	)
 
	on Dist close do
	(
		$PhysCamera001.clip_on = off
		MC.active = false
	)
)
createDialog Dist