GetTrainSpeed

function getPlayersTrainSpeed ( source, command ) -- Define source in the function header.
	if ( isPedInVehicle ( source ) ) -- Check if they're in a vehicle.
	local veh = getPedOccupiedVehicle ( source ) -- Get the vehicle they're in.
		if ( getVehicleType ( veh ) == "Train" ) then -- Check if the vehicle they're in is a train.
			local speed = getTrainSpeed ( veh ) -- Get the trains speed.
			outputChatBox ( "You are travelling at a speed of " .. speed, source, 255, 0, 0 ) -- Output their speed.
		else
			outputChatBox ( "You must be in a train to use this command.", source, 255, 0, 0 ) -- Tell them they're not in a train.
		end
	else
		outputChatBox ( "You must be in a train to use this command.", source, 255, 0, 0 ) -- Tell them they're not in a train.
	end
end
addCommandHandler ( "speed", getPlayersTrainSpeed ) -- Make the function trigger when a player types "/speed".