Splitting strings with a delimiter

When I do:

local ip_split = String.split("10.11.12.13","\.",3)[1]

I get the error message:

attempt to index a string value
        site:/hi.html.luan line 43

If I just do local ip_split = String.split("10.11.12.13","\.",3), it seems to set ip_split to the string "10". How do I get 11, 12, and 13 from the string?

tt.luan

It works, thanks.