Help on gun script?

I have an auto script but it doesn't work online because of the mouse but works on solo(studio). Any solutions? Here's my script.

local tool = script.Parent
local user

--when the tool is equipped
tool.Equipped:connect(function(mouse)
   --store the character of the person using the tool
   user = tool.Parent 

   --when the left mouse button is clicked
local autofire = false
    tool.Activated:connect(function() 
            if not autofire then
                autofire = true
            while autofire do
                wait(.15)
        local fire = Instance.new("Sound")
        fire.SoundId = "http://roblox.com/asset/?id=10209875"
        fire.Volume = 0.5
        fire.Parent = game.Workspace
        fire:play()
       --make and do a hit test along the ray
        if mouse then
       local ray = Ray.new(tool.Handle.CFrame.p, (mouse.Hit.p - tool.Handle.CFrame.p).unit*300)
       local hit, position = game.Workspace:FindPartOnRay(ray, user)

       --do damage to any humanoids hit
       local humanoid = hit and hit.Parent and hit.Parent:FindFirstChild("Humanoid")
       if humanoid then
           humanoid:TakeDamage(5)
       end

       --draw the ray
       local distance = (position - tool.Handle.CFrame.p).magnitude
       local rayPart = Instance.new("Part", user)
       rayPart.Name          = "RayPart"
       rayPart.BrickColor    = BrickColor.new("Bright yellow")
       rayPart.Transparency  = 0.5
       rayPart.Anchored      = true
       rayPart.CanCollide    = false
       rayPart.TopSurface    = Enum.SurfaceType.Smooth
       rayPart.BottomSurface = Enum.SurfaceType.Smooth
       rayPart.formFactor    = Enum.FormFactor.Custom
       rayPart.Size          = Vector3.new(0.2, 0.2, distance)
       rayPart.CFrame        = CFrame.new(position, tool.Handle.CFrame.p) * CFrame.new(0, 0, -distance/2)

       --add it to debris so it disappears after 0.1 second
       game.Debris:AddItem(rayPart, 0.1)
                    end
                end
            end
       end)
    tool.Deactivated:connect(function()
        autofire = false
    end)        
end)

Please help. The problem has something to do with the mouse that's it.