Upgrading the house

ID:268802
 
Nov 18 2004, 2:55 pm
 
mob/verb/Configure_House(obj/O as obj in oview(1))
   switch(alert("Would you like to destroy this house or upgrade it?",,"Upgrade","Destroy"))
      if("Upgrade")
         src << "You upgrade the house."
         upg += 1
         UPG_CHECK()
         O.icon_state = "TEC2"
      if("Destroy")
         del(O)
mob
    var
     upg
     
mob/proc/UPG_CHECK(obj/O as obj in oview(1))
    if(upg == 2)
        O.icon_state = "TEC3"
    if(upg == 3)
        O.icon_state = "TEC4"
    if(upg == 4)
        O.icon_state = "TEC5"
    else
        ..()


I'm trying to make it so when it upgrades, it gets a different icon state, but I get this when I try upgrading twice and on.

runtime error: Cannot modify null.icon_state.
proc name: UPG CHECK (/mob/proc/UPG_CHECK)
usr: Merciless Warrior (/mob)
src: Merciless Warrior (/mob)
call stack:
Merciless Warrior (/mob): UPG CHECK(null)
Merciless Warrior (/mob): Configure House(House (/obj/House))

Please help if you can.
Nov 18 2004, 3:01 pm
You are calling UPG_CHECK() without a required argument (obj/O).

I suggest you turn debugging on an review your error messages a bit more carefully; this one told you exactly what was wrong.
Nov 18 2004, 3:20 pm
In response to Jmurph
I see your point. Thanks.
Nov 18 2004, 7:28 pm
In response to Merciless Warrior
No problem. Good luck!