attempt to concatenate a nil value in HUD

Im making hud and when i joining my server it’s creates errors.

[ERROR] gamemodes/darkrp/gamemode/modules/mymodules/sh_doors.lua:274: attempt to concatenate a nil value
  1. fn - gamemodes/darkrp/gamemode/modules/mymodules/sh_doors.lua:274
   2. unknown - addons/ulib/lua/ulib/shared/hook.lua:183


draw.DrawText("Money: "..LocalPlayer():getDarkRPVar("money").."$ + ".. LocalPlayer():getDarkRPVar("salary").."$","DermaDefaultBold", 200, ScrH() - 45, Color(100,100,100), TEXT_ALIGN_LEFT)

LOL fixed it in 10 seconds after posting thread.