minetest.register_on_joinplayer(function(player)

        local minp={x=500, y=-100, z=500}
        local maxp={x=500, y=100, z=500}

        minetest.emerge_area(minp, maxp)

        for cy=minp.y, maxp.y do
            pos={x=500, y=cy, z=500}
            if minetest.forceload_block(pos) then
                node = minetest.get_node(pos)
                minetest.chat_send_all("Y=" .. cy .. "> " .. node.name)
            else
                minetest.chat_send_all("Y=" .. cy .. "> could not force load")
            end
        end
end)