ScrW problem

function SWEP:DrawHUD(cr)
if cr == 1 then
–gets the center of the screen
local x = ScrW() / 2.0
local y = ScrH() / 2.0
local fth = ScrW() / 4
local fthy = Scrh() / 4

--set the drawcolor
surface.SetDrawColor( 255, 255, 255, 255 )

local gap = 5
local length = gap + 15

--draw the crosshair
surface.DrawLine( x - length, y, x - gap, y )
surface.DrawLine( x + length, y, x + gap, y )
surface.DrawLine( x, y - length, x, y - gap )
surface.DrawLine( x, y + length, x, y + gap )
    surface.DrawOutlinedRect(  fth, fthy / 4, y, x );
end

cr = 0
end

when i run this, console says that scrw is nil or something. any help?]

NOOO!!! i posted in the wrong section…