Dominating Hitsound LUA

callbacks = variables.Callbacks
engine = variables.Interfaces:Engine()

sound = "music\\dominating"
name = "dominating"

gui = variables.gui
gui:AddOption("hitsound", name)

function onevent()
    if variables.event:GetName() == "player_hurt" then --someone hurt someone else
        attacker = engine:PlayerForUserID(variables.event:GetInt("attacker"))
        if attacker == engine:LocalPlayer() then --localplayer hurt someone else
            if gui:SelectedOption("hitsound", name) then --our custom hitsound is enabled
                engine:ExecuteCommand("playvol " .. sound .. " " .. gui:GetValue("hitsound_volume") * .01) --play our defined sound using the volume from the slider in the ui
            end
        end
    end
end

callbacks:Register(variables.GAMEEVENT, "onevent")