on_receive_fields = function(pos, formname, fields, sender)
        local inv = minetest.get_inventory({type = "node", pos = pos})
        --
        if inv:is_emtpy("streets:signworkshop_input") ~= true then
            if inv:get_list("streets:signworkshop_input") == inv:get_list("streets:signworkshop_recipe") then
                minetest.chat_send_all("ok")
            end
        end
    end