SWEP opens derma panel

[Jabbers]

Can someone explain why this does not open the derma panel ? It is in my SWEP, shared.lua.
function SWEP:PrimaryAttack()

if CLIENT then

local EMSInventory = vgui.Create( "DFrame" )

EMSInventory:SetTitle( "EMS Inventory" )
EMSInventory:SetSize( 300, 150 )
EMSInventory:Center()
EMSInventory:MakePopup()
EMSInventory:ShowCloseButton( false )
EMSInventory.Paint = function(s , w, h)

draw.RoundedBox(5,0,0,w , h,Color(255,120,120))
end

end 

[SweptThrone]

Because, from the PrimaryAttack wiki page:
When in singleplayer, this function is only called in the server realm.

[Jabbers]

Thanks. How do I close this ?