HopperBin Fireball Script Not Working?

So, I am making a game with a hopperbin in the starterpack. I used the boulder script from the roblox developer wiki, and made it transparent, but I want it to be on fire too (like fireballs). This is the script, I made the fire, but I can't put it in the thingy that pops up (I tried though). Please help!

lifetime = 5 -- how long the boulder stays there. 5 is a good value.
 
function onButton1Down(mouse)
	local b = Instance.new("Part")
	local bfire = Instance.new(b."Fire")
	b.BrickColor = BrickColor.new(217)
	b.Transparency = 0
	b.Position = mouse.Hit.p
	b.Size = Vector3.new(5, 5, 5)
	b.Shape = 0
	b.Parent = game.Workspace
	b.Velocity = (script.Parent.Parent.Parent.Character.Head.Position - mouse.Hit.p).unit * -50 + Vector3.new(0, 10, 0)
	-- pushes it away from you, and pops it up a bit, making it seem to come out of the ground.
	game:GetService("Debris"):AddItem(b, lifetime)
end
 
function onSelected(mouse)
	mouse.Button1Down:connect(function() onButton1Down(mouse) end) -- Button1Down doesn't come with a mouse, seeing as its
	-- an event of the mouse itself. We need to give the function the mouse object to work off of.
end
 
script.Parent.Selected:connect(onSelected) -- Selected comes with a mouse.