Map help on ttt

How do i make it so the map never changes i have got it so it is always on the same map, but it “changes” every 6 rounds. how do i for example change this to every 5000 rounds or 1000000 hours? Thanks

[editline]19th February 2013[/editline]

Also, the map is on fastdl, however is says “missing map”

ttt_round_limit 6000
tt_time_limit_minutes 10000000000000000000000000000000000000000

make sure your downloadurl is correct and points to the right directory.