Look at the code that i used with the help

Summon_Bass(mob/M in oview(2))
if(usr.Custom >= 200)
var/bshot = 'bshot.dmi'
var/mob/W = locate(/mob in oview(3))
var/mob/Y = locate(/mob in oview(2))
var/mob/Z = locate(/mob in oview(1))
set category = "Fight"
var/temp = usr.icon // hold the icon in a variable
usr.icon = 'bass_summ.dmi'
spawn(15)
view(5)<<"[usr] : Multi Gun!!!! "
M.overlays += bshot
W.overlays += bshot
Y.overlays += bshot
Z.overlays += bshot
M.HP -= 220
W.HP -= 220
Y.HP -= 220
Z.HP -= 220
M.overlays -= bshot
W.overlays -= bshot
Y.overlays -= bshot
Z.overlays -= bshot
spawn(5)
usr.icon = temp // revert the icon back
usr.Custom -= 200
else
usr << "You Dont Have Enough Custom!"



error when i used:




runtime error: Cannot read null.overlays
proc name: Summon Bass (/obj/Bass_Summon_chip/verb/Summon_Bass)
source file: SkillGain.dm,622
usr: Pharaoh Atem (/mob/Player)
src: Bass Summon chip (/obj/Bass_Summon_chip)
call stack:
Bass Summon chip (/obj/Bass_Summon_chip): Summon Bass(Chaos License Quest (/mob/NPC/Chaos_License_Quest))
Pharaoh Atem : Multi Gun!!!!


help plz!!!

i arent too good in english, im br!
*edit*i cant understand the guide, and a few of the answers =( ...