[LUA PROBLEM] Usable Entity Derma Problem.

I am currently working on a Vending machine for DarkRP (Yeah yeah.)
Anyways, this is my first attempt at using derma screens. So currently the idea is that when I ‘use’ the vending machine a single derma screen will appear.
The problem is that when I use it, multiple derma screens appear. This changes based on how long I hold it.

Here is the code:
init.lua -
[lua] AddCSLuaFile( “cl_init.lua” )
AddCSLuaFile( “shared.lua” )

include(‘shared.lua’)

function ENT:Initialize()
self:SetModel(“models/props_interiors/VendingMachineSoda01a.mdl”)
self:PhysicsInit(SOLID_VPHYSICS)
self:SetMoveType(MOVETYPE_VPHYSICS)
self:SetSolid(SOLID_VPHYSICS)
local phys = self:GetPhysicsObject()
if phys:IsValid() then phys:Wake() end
end

function ENT:AcceptInput( Name, Activator, Caller )
if Name == “Use” and Caller:IsPlayer() then
umsg.Start(“displayvend”, Caller)
umsg.End()

end

end
[/lua]

cl_init.lua -
[lua]

include(‘shared.lua’)

function DisplayVend()

local pShop = vgui.Create('DFrame')
pShop:SetSize(330, 400)
pShop:SetPos(ScrW()-850, ScrH()-600)
pShop:SetTitle('Vendor')
pShop:SetSizable(true)
pShop:SetDeleteOnClose(false)
pShop:MakePopup()

end

usermessage.Hook(“displayvend”, DisplayVend) [/lua]

I think that I may need to have a sort of ‘delay’ in between presses. Sadly I do not know how. :frowning:
Can anyone help me. I would be thankful.

self:SetUseType( SIMPLE_USE )

You have just made my day. Thankyou. <3