function mval(amount)
        local substrings = {}
        local rest = amount  
        local result
        
        while string.len(rest) > 2 do
                local restlen = string.len(rest)
                table.insert(substrings, 1, string.sub(rest, restlen-2))
                rest = string.sub(rest, 1, restlen-3)
        end
        
        if string.len(rest) > 0 then table.insert(substrings, 1, rest) end
        
        for i,v in ipairs(substrings) do
                result = result and (result..","..v) or v
        end
        return result
end