Player xp bar, need help with some math

[grunewald]

i am having a hard time trying to find out what should i do to make it work

ive deleted my stupid math since it din't work.. this is how the script looks :)
ehm when CurXp = 250 amd NextLvlXp is 500 the bar should be half full no matter the screen resolution

[lua]
local Text = "Level: 1"

local function ShowPlyXp()
local H = ScrH()
local W = ScrW()
local H1P = H/100
local W1P = W/100

local CurXp = 250
local NextLvlXp = 500

local WidthStatus = CurXp

draw.RoundedBox( 6, W1P*30, H1P*4.16, W/2.5, 20, Color( 0, 0, 0, 180 ) )
draw.RoundedBox( 6, W1P*30, H1P*4.16, math.Clamp( WidthStatus, 12, W/2.5 ), 20, Color( 0, 255, 165, 150 ) )

surface.SetTextPos( W1P*32, H1P*4.16 )
surface.SetFont("Trebuchet19")
surface.SetTextColor( 255, 255, 255, 255 )
surface.DrawText( Text )

surface.SetTextPos( W/2, H1P*4.16 )
local text = CurXp .. "/" .. NextLvlXp
surface.DrawText( text )

end
hook.Add( "HUDPaint", "tell's the palyer how much xp he got, and how much is for next lvl", ShowPlyXp )
[/lua]

ive just taking this from another of my scripts, normally the bar is a timer lawl :P

[Panto]

[lua]
local padding = 4
local w, h = ScrW() / 4, 25
local x, y = 20, ScrH() - 25 - h
local barWidth = ply.CurXP / ply.DesiredXP

draw.RoundedBox( 4, x, y, w, h, Color(0, 0, 0, 180) ) --Draw background.
draw.RoundedBox( 4, x + padding, y + padding, (w - padding * 2) * barWidth, h - padding * 2, Color(0, 255, 165, 150) ) --Draw inner.
[/lua]