Why doesn't my script damage players sometimes?

This script damages any player that is hit by it, but if the player with the weapons stays still it instead passes through them without doing any damage...

local modelstuff = {}
function ontouch(hit)
if hit.Parent:FindFirstChild("Humanoid") then
local model = hit.Parent
local hum = hit.Parent:FindFirstChild("Humanoid")
		if modelstuff[model] then
		return
		else
			local def = hit.Parent:FindFirstChild("Defense").Value
			local dmg = script.Parent.Parent:WaitForChild("Attack").Value - def
			hum:TakeDamage(dmg)
			if hit.Parent:FindFirstChild("Bleed") then
				if hit.Parent:FindFirstChild("Streak") then
					else
				local streak = Instance.new("IntValue")
				streak.Parent = hit.Parent
				streak.Name = "Streak"
				end
				local st = hit.Parent:FindFirstChild("Streak")
				st.Value = st.Value + 1
				hit.Parent:FindFirstChild("Bleed").Dmg.Value = hit.Parent:FindFirstChild("Bleed").Dmg.Value + 1
				hit.Parent:FindFirstChild("Bleed").Time.Value = hit.Parent:FindFirstChild("Bleed").Time.Value + 1
				local bled = hit.Parent:FindFirstChild("Head").Bleed
				bled.TextLabel.Text = "Bleed X".. st.Value
			else
				local bleed = game.ServerStorage.Effects.Bleed:Clone()
				bleed.Disabled = false
				bleed.Parent = hit.Parent
			end
			local h = hit.Parent:FindFirstChild("HumanoidRootPart")
			local bb = game.ServerStorage.Classes.BillboardGui:Clone()
			bb.Parent = h
			local txtlabel = bb:WaitForChild("TextBox")
			if dmg > 20 then
				txtlabel.TextColor3 = Color3.fromRGB(255,0,0)
			end
			txtlabel.Text = tostring(dmg)
		end
		modelstuff[model] = true
		wait(.5)
		modelstuff[model] = false
end
end
script.Parent.DmgBox.Touched:Connect(ontouch)

Please help me, i cant script