How do I prevent passing an argument through as a instance instead of a integer?[Solved in comments]

Edit: This got solved in the comments, edited the title to include grammar mistakes so I'm within the character limit.

Hi!

I'm trying to get a player to drop a bomb when pressing space. I'm currently handling this with the FireServer function and putting in the player's userid in as argument.

During this the argument seems to have become an instance instead to an integer. Since I require an integer instead of an Instance, the script breaks and cannot continue.

The localscript that fires the event when pressing space:

local input = game:GetService("UserInputService")

while not input.KeyboardEnabled do
    wait()
end

local keyboard = input.KeyboardEnabled

while true do

    if keyboard and input:IsKeyDown(32) then --Check if space is pressed

        id = game.Players.LocalPlayer.UserId

        game.Workspace.Bombhandle:FireServer(id)
        print(id) --When starting a local server for testing this returns -1
        wait(0.3) --Cooldown

    end

    wait()

end

And the server sided script:

--Handles the server side of placing a bomb when receiving a fire event from the remote event.

local event = game.Workspace.Bombhandle

event.OnServerEvent:connect(function(userid)

    local chr = game.Players:GetPlayerByUserId(userid).Character --This line returns the error "Unable to cast Instance to int"

    --TODO check if the player has the amount of bombs required


    --Get the variables we need to have the bomb in proper
    local Power = chr.Stats.Pwr.Value
    local Range = chr.Stats.Rng.Value
    local Pos = chr.Torso.Position

    --Create the bomb, but don't place it in yet.
    local bomb = game.ReplicatedStorage.BombBall:Clone()

    --Set up the bomb values.
    bomb.Pwr.Value = Power
    bomb.Rng.Value = Range
    bomb.Position = Pos

    --And now put it in the game
    bomb.Parent = game.Workspace

end)