My follow script

torso = script.Parent.Torso
maxrange = 70
minrange = 20
target = nil
tor = nil
head = script.Parent.Head

torso.BodyPosition.position = Vector3.new(0,head.Position.Y+10,0)

function findNearestTarget()
	plrs = game.Players:GetChildren()
	for i, plr in ipairs(plrs) do
		if plr.Character ~= nil then
			if plr.Character:findFirstChild("Humanoid") and plr.Character.Humanoid.Health>0 then
				if plr.Character:findFirstChild("Torso") then
					tor = plr.Character.Torso
				end	
				if target == nil then
					if ((torso.Position - tor.Position).magnitude <= maxrange)  then
						if ((torso.Position - tor.Position).magnitude >= minrange) then
							target = plr.Character
						else
							target = nil
							script.Parent.Zombie:MoveTo(script.Parent.Head.Position, script.Parent.Head)
						end		
					else
						target = nil
						script.Parent.Zombie:MoveTo(script.Parent.Head.Position, script.Parent.Head)
					end
				end
			end
		end
	end
end

while true do 
	wait(.1)
	findNearestTarget()
	if target ~= nil then
		if ((torso.Position - tor.Position).magnitude <= maxrange) and ((torso.Position - tor.Position).magnitude >= minrange) then
			script.Parent.Zombie:MoveTo(target.Torso.Position, target.Torso)
			script.Parent.Torso.BodyPosition.position = Vector3.new(0,tor.Position.Y,0)
		else
			target = nil
		end
	else
		target =nil
	end		
end

So, what i want is that the humanoid keeps constantly focused at its target, aka, looking at the target. I really don't understand to much humanoids, so can someone tell me how to make the humanoid constantly looking at the target?