I can't find out an NPC's Def in scripting can somebody help?

[Syner]

Sub OnAttack(Index, Damage)
Dim Target
Dim Range
Dim Level
Dim Power

If Int(GetPlayerTarget(index))  > 0 Then
    Range = Rand(Int(GetPlayerSTR(index) + Int(Damage)) + GetPlayerLevel(Target), Int(GetPlayerSTR(index)+ Int(Damage))  - GetPlayerDef(Target))
End If
If Int(GetPlayerTarget(index)) < 0 Then
    Range = Rand(Int(GetPlayerSTR(index) + Int(Damage)) + GetPlayerLevel(index), Int(GetPlayerSTR(index)+ Int(Damage)) - GetPlayerLevel(index))
End If

  If Int(Range) > 0 Then
      If Int(GetPlayerTarget(Index)) > 0 Then
        Target = GetPlayerTarget(Index)
        Call DamagePlayer(Index, Target, Range)
      Else
        Target = GetPlayerTargetNPC(Index)
        Call DamageNPC(Index, Target, Range)
      End If
  Else
      If Int(GetPlayerTarget(Index)) > 0 Then
        Target = GetPlayerTarget(Index)
        Call DamagePlayer(Index, Target, 0)
      Else
        Target = GetPlayerTargetNPC(Index)
        Call DamageNPC(Index, Target, 0)
      End If

  End If
End Sub

I'm trying to change up somebody's damage range skill and incorporate def in the equation for NPC and players but I can't get the scripts to return the NPC def to givew the damage

[Nubbs]

GetNpcDef(index) or GetNpcDef(map,npcnum) sorry im not on my comp so io cant be sure which one