Where i need to change humanoid on zombie?

Hello everyone, I have problem with script in gun. I want to change humanoid on zombie, becouse monsters hitting other monsters, so it's anoying. When i change in monster humanoid on zombie - i can't hurt them... It's not my script. Weapon created by WIJ. It's not all script, becouse max characters are 10,000, but i think in these lines. Here is script, if someone can show/write me where should i change :

------------------------------------------------------------------------------------Raycasting functions
 function raycast(startp, endp, ign)
	local vec=(endp-startp)
	if vec.magnitude<1000 then
	local hit,pos=game.Workspace:FindPartOnRay(Ray.new(startp,vec),ign)
	if hit and pos then
		if hit.Parent.className=="Tool" or hit.Parent.className=="Hat" then
			if hit.Parent.Parent ~= nil then
			if hit.Parent.Parent:findFirstChild("Humanoid")~=nil then
			return hit.Parent, pos
			end
			end
		elseif string.lower(hit.Name)=="glass" then
			local vec=(endp-pos)
			hit,pos=raycast(pos,vec,ign)
		elseif string.lower(hit.Name)=="water" then
			local vec=(endp-pos)
			hit,pos=raycast(pos,vec,ign)
		elseif hit.Transparency==1 or hit.Name=="Bullet" or hit.Name=="BulletTexture" then
			local vec=(endp-pos)
			hit,pos=raycast(pos,vec,hit)
		end
	end
	return hit,pos
	end
	return nil
end
-------------------------------------------------------------------------------






function tagHumanoid(humanoid)
	local plr=game.Players:playerFromCharacter(sp.Parent)
	if plr~=nil then
		local tag=Instance.new("ObjectValue")
		tag.Value=plr
		tag.Name="creator"
		tag.Parent=humanoid
		delay(2,function()
			if tag~=nil then
				tag.Parent=nil
			end
		end)
	end
end

function onKeyDown(key,mouse)
	key=key:lower()
	--[[if key=="r" and not reloading then
		reload(mouse)
	end]]
end

function movecframe(p,pos)
	p.Parent=game.Lighting
	p.Position=pos
	p.Parent=game.Workspace
end


function checkAllyWIJ(killer, victim)
if game:findFirstChild("Teams")~=nil then
	if killer ~= victim then
		if killer.TeamColor==BrickColor.new("Bright blue") and victim.TeamColor==BrickColor.new("Bright green") then 
		return true
		elseif killer.TeamColor==BrickColor.new("Bright green") and victim.TeamColor==BrickColor.new("Bright blue") then
		return true
		elseif killer.TeamColor == victim.TeamColor then
		return true
		else
		return false
		end
		return false
	else
	return true
	end
	return false
else
return false
end
end

function takeDamage(dm, pl)
if pl:findFirstChild("Shield")~=nil then
sh=pl:findFirstChild("Shield")
	if sh.Value==0 then
	pl.Humanoid:TakeDamage(dm)
	elseif sh.Value<dm then
	newdm=dm-sh.Value
	sh.Value=0
	pl.Humanoid:TakeDamage(newdm)
	elseif sh.Value>dm then
	sh.Value=sh.Value-dm
	elseif sh.Value==dm then
	sh.Value=0
	end
else
pl.Humanoid:TakeDamage(dm)
end
end

function fire(aim)
	script.Parent.Handle.Fire.Pitch=(math.random(-5,-1)/10)+1
	sp.Handle.Fire:Play()

	local bullet=Bullet:clone()
	--[[local bt2=game.Lighting.BulletTexture:clone()
	bt2.BrickColor=BrickColor.new("Bright red")
	bt2.Mesh.Scale=Vector3.new(.5,.5,2)]]--
	local totalDist=0
	Lengthdist=-RayLength/.5
	local startpoint=sp.Handle.CFrame*BarrlePos
	local direction=(aim-startpoint)
	local cfrm=CFrame.new(startpoint, direction+startpoint)
	local vector=startpoint+(direction.Unit*999)
		if (startpoint-vector).magnitude<1000 then
			if game.Workspace:FindPartOnRay(Ray.new(player.Character.Head.Position,startpoint-player.Character.Head.Position),player.Character)==nil then
			local hit,pos=raycast(startpoint,vector,player.Character)
			bullet.Parent=game.Workspace
			--bt2.Parent=game.Workspace
			if hit~=nil then
				if hit.Parent:FindFirstChild("VecHealth")~=nil then
				vech=hit.Parent:FindFirstChild("VecHealth")
				vech.Value=vech.Value-VehicleDamage
				end
				if hit.Parent:FindFirstChild("HealthStatus")~=nil then
				fo=hit.Parent:FindFirstChild("HealthStatus")
				fo.Value=fo.Value-BaseDamage
				end
				local humanoid=hit.Parent:FindFirstChild("Humanoid")
				if humanoid~=nil then
					local damage=math.random(BaseDamage-(BaseDamage*.25),BaseDamage+(BaseDamage*.25))
					if hit.Name=="Head" then
						damage=damage*1.25
					elseif hit.Name=="Torso" then
					else
						damage=damage*.75
					end
					if humanoid.Health>0 then
						local eplr=game.Players:playerFromCharacter(humanoid.Parent)
						local plr=game.Players:playerFromCharacter(sp.Parent)
						if eplr~=nil and plr~=nil then
						if (checkAllyWIJ(plr, eplr)==false) then
								if hit.Parent:findFirstChild("ForceField")==nil then
								tagHumanoid(humanoid)
								takeDamage(damage, humanoid.Parent)
								sX=sfx:clone()
								sX.Parent=player
								sX:play()
								end
						end
						else
							if hit.Parent:findFirstChild("ForceField")==nil then
							tagHumanoid(humanoid)
							takeDamage(damage, humanoid.Parent)
							sX=sfx:clone()
							sX.Parent=player
							sX:play()
							end
						end
					end
				end
				distance=(startpoint-pos).magnitude
				bullet.CFrame=cfrm*CFrame.new(0,0,-distance/2)
				bullet.Mesh.Scale=Vector3.new(.15,.15,distance)
			else
				bullet.CFrame=cfrm*CFrame.new(0,0,-RayLength/2) 
				bullet.Mesh.Scale=Vector3.new(.15,.15,RayLength)
			end
			if pos~=nil then
				--bt2.CFrame=bullet.CFrame
				--movecframe(bt2,pos)
			end
			local deb=game:FindFirstChild("Debris")
			if deb==nil then
				local debris=Instance.new("Debris")
				debris.Parent=game
			end
			check()
			game.Debris:AddItem(bullet,.05)
			game.Debris:AddItem(sX, .3)
			--game.Debris:AddItem(bt2,.5)
		end
	end
end

function onButton1Up(mouse)
	down=false
end

function onButton1Down(mouse)
	h=sp.Parent:FindFirstChild("Humanoid")
	if not enabled or reloading or down or h==nil then
		return
	end
	if Charge.Value<MaxCharge and h.Health>0 and overheated==false and battery==true then
		--[[if sp.Ammo.Value<=0 then
			if not reloading then
				reload(mouse)
			end
			return
		end]]
		down=true
		enabled=false
		while down do
			if Charge.Value>=MaxCharge or sp.Parent:FindFirstChild("Humanoid")==nil or overheated == true then
				break
			end
			sfd=sfd+1
			if sfd>=shotsForDepl then
			sfd=0
			batteryLife.Value=batteryLife.Value-math.random(minDepletion, maxDepletion)
			end
			if burst then
				local startpoint=sp.Handle.CFrame*BarrlePos
				local mag=(mouse.Hit.p-startpoint).magnitude
				local rndm=Vector3.new(math.random(-(Spread/10)*mag,(Spread/10)*mag),math.random(-(Spread/10)*mag,(Spread/10)*mag),math.random(-(Spread/10)*mag,(Spread/10)*mag))
				fire(mouse.Hit.p+rndm)
				Charge.Value=Charge.Value+math.random(chargeperfireMIN, chargeperfireMAX)
				if Charge.Value>=MaxCharge then
					break
				end
				wait(.05)
				local startpoint=sp.Handle.CFrame*BarrlePos
				local mag2=((mouse.Hit.p+rndm)-startpoint).magnitude
				local rndm2=Vector3.new(math.random(-(.1/10)*mag2,(.1/10)*mag2),math.random(-(.1/10)*mag2,(.1/10)*mag2),math.random(-(.1/10)*mag2,(.1/10)*mag2))
				fire(mouse.Hit.p+rndm+rndm2)
				Charge.Value=Charge.Value+math.random(chargeperfireMIN, chargeperfireMAX)
				if Charge.Value>=MaxCharge then
					break
				end
				wait(.05)
				fire(mouse.Hit.p+rndm+rndm2+rndm2)
				Charge.Value=Charge.Value+math.random(chargeperfireMIN, chargeperfireMAX)
			elseif shot then
				Charge.Value=Charge.Value+math.random(chargeperfireMIN, chargeperfireMAX)
				local startpoint=sp.Handle.CFrame*BarrlePos
				local mag=(mouse.Hit.p-startpoint).magnitude
				local rndm=Vector3.new(math.random(-(Spread/10)*mag,(Spread/10)*mag),math.random(-(Spread/10)*mag,(Spread/10)*mag),math.random(-(Spread/10)*mag,(Spread/10)*mag))
				fire(mouse.Hit.p+rndm)
				local mag2=((mouse.Hit.p+rndm)-startpoint).magnitude
				local rndm2=Vector3.new(math.random(-(.2/10)*mag2,(.2/10)*mag2),math.random(-(.2/10)*mag2,(.2/10)*mag2),math.random(-(.2/10)*mag2,(.2/10)*mag2))
				fire(mouse.Hit.p+rndm+rndm2)
				local rndm3=Vector3.new(math.random(-(.2/10)*mag2,(.2/10)*mag2),math.random(-(.2/10)*mag2,(.2/10)*mag2),math.random(-(.2/10)*mag2,(.2/10)*mag2))
				fire(mouse.Hit.p+rndm+rndm3)
				local rndm4=Vector3.new(math.random(-(.2/10)*mag2,(.2/10)*mag2),math.random(-(.2/10)*mag2,(.2/10)*mag2),math.random(-(.2/10)*mag2,(.2/10)*mag2))
				fire(mouse.Hit.p+rndm+rndm4)
			else
				Charge.Value=Charge.Value+math.random(chargeperfireMIN, chargeperfireMAX)
				local startpoint=sp.Handle.CFrame*BarrlePos			
				local mag=(mouse.Hit.p-startpoint).magnitude
				local rndm=Vector3.new(math.random(-(Spread/10)*mag,(Spread/10)*mag),math.random(-(Spread/10)*mag,(Spread/10)*mag),math.random(-(Spread/10)*mag,(Spread/10)*mag))
				fire(mouse.Hit.p+rndm)
			end
			
			wait(Firerate)
			if not automatic or battery==false then
				break
			end
			if down==true then
			wait(.06)
			end
		end	
		enabled=true
	else
		sp.Handle.Trigger:Play()
	end
end

function onEquippedLocal(mouse)
	if mouse==nil then
		print("Mouse not found")
		return 
	end
	script.GunGui:clone().Parent=player.PlayerGui
	mouse.Icon=Cursors[1]
	mouse.KeyDown:connect(function(key) onKeyDown(key,mouse) end)
	mouse.Button1Down:connect(function() onButton1Down(mouse) end)
	mouse.Button1Up:connect(function() onButton1Up(mouse) end)
	equiped=true
	down=false
	check()
end
function onUnequippedLocal(mouse)
		if player.PlayerGui:FindFirstChild("GunGui")~=nil then
		player.PlayerGui:FindFirstChild("GunGui").Parent=nil	
		end
	equiped=false
	reloading=false
	down=false
	sp.Name = OriginalToolName
end
sp.Equipped:connect(onEquippedLocal)
sp.Unequipped:connect(onUnequippedLocal)
check()