How to create a command.

[PeterP]

function getPlayerID(id)
	v = false
	for i, player in ipairs (getElementsByType("player")) do
		if getElementData(player, "ID") == id then
			v = player
			break
		end
	end
	return v
end


addEventHandler("onViatura", root,
	function()
		local receiver = getElementData(source, "ReceiverPM")
		local vtr      = carros[source]
		if (receiver) and (vtr) then
			local vrx, vry, vrz = getElementRotation(vtr)
    		local px, py, pz    = getElementPosition(vtr)
			if not getElementData(receiver, "NaViatura") then
				if not isPedInVehicle(receiver) then
					setElementData(receiver, "NaViatura", true)
					message(source, "O jogador foi colocado na viatura.", "success")
					message(receiver, "Você foi colocado na viatura!", "info")

					attachElements(receiver, vtr, 0.2, -1.5, 0, 0,0,90)
            		setPedAnimation(receiver, 'ped','CAR_dead_LHS')
            		setElementRotation(receiver, vrx, vry, vrz + 83)
            	end
			else
				setElementData(receiver, "NaViatura", nil)
				message(source, "O jogador foi retirado da viatura.", "success")
				message(receiver, "Você foi retirado da viatura!", "info")

				detachElements(receiver, getElementAttachedTo(receiver))
				setElementPosition(receiver, px + 2, py + 2, pz)
				setPedAnimation(receiver)
			end
		end
	end
)

This function was originaly created to lock a player in the car using the mouse cursor, but it's not possible to release the player once he's in the car because I can't click on them. 

How can I create a command using the player's ID to realease him ?

Thank you very much.