Runtime Error [SOLVED]

ID:141526
 
Feb 6 2009, 7:15 am (Edited on Feb 6 2009, 9:01 am)
This is the code where the problem happends:

                    if(M.Powerlevel<=10)//THIS IS THE CODE THAT IT POINTS TO
                        usr.Enemies_Killed += 1
                        usr << "You Defeated [M], You gain <B><U>[commas(num2text(round(M.Zeni),99999999))] Zeni</U></B> and <B><U>[commas(num2text(round(M.MaxExp),99999999))] Exp</B></U>"
                        usr.Exp += M.MaxExp
                        usr.Zeni += M.Zeni
                        usr.LevelUp()
                        del(M)
                        return

The runtime error says:

runtime error: Cannot read null.Powerlevel
proc name: Kick (/mob/verb/Kick)
source file: Combat.dm,154
usr: Guest-2520799949 (/mob/Player)
src: Guest-2520799949 (/mob/Player)
call stack:
Guest-2520799949 (/mob/Player): Kick(null)
Feb 6 2009, 7:17 am
Show what's before that line.
Feb 6 2009, 7:19 am
Your issue is exactly as described: M is null.

Without the code preceeding the error and the context its impossible to determine why.
Feb 6 2009, 7:25 am
In response to Alathon
I know it's null because when I kill the monster/NPC it will delete it and my attacking is set as a macro which people tend to press the button after the NPC/Monster is destroyed, which causes the runtime error.
Feb 6 2009, 7:29 am
In response to Andre-g1
I know the coding ain't the best but you can make comments on anything.

                if(M.Monster == 1)
                    M.Attacked = 1
                    var/dmg = usr.Strength
                    M.overlays = /obj/Punched
                    M.Powerlevel -= dmg
                    usr.overlays = /obj/Combat
                    M.dir = get_dir(M,usr)
                    F_damage(M, dmg, color = "#ff0000")
                    usr.icon_state = "punch1"
                    sleep(4)
                    usr.icon_state = ""
                    view(usr)<<'hit1.wav'
                    if(M.Powerlevel<=10) // This is where the problem occurs.
                        usr.Enemies_Killed += 1
                        usr << "You Defeated [M], You gain <B><U>[commas(num2text(round(M.Zeni),99999999))] Zeni</U></B> and <B><U>[commas(num2text(round(M.MaxExp),99999999))] Exp</B></U>"
                        usr.Exp += M.MaxExp
                        usr.Zeni += M.Zeni
                        usr.LevelUp()
                        del(M)
                        return
Feb 6 2009, 7:35 am
In response to Gizhy
Gizhy wrote:
I know it's null because when I kill the monster/NPC it will delete it

Well then what you need to do is double-check that M even exists and not delete M before you're done with it.
Feb 6 2009, 7:40 am
In response to Alathon
Can you help me out by showing some sort of example?
Feb 6 2009, 10:31 am
In response to Gizhy
Show us where M is actually defined, like is it a param (mob/M), or is it pure declaration 'var/mob/M = new'

Etc.
Feb 6 2009, 11:46 am
In response to Haywire
I already fixed the prob, but thanks for the reply.