https://www.zombiemodding.com/index.php?topic=3884.0scroll down to the comments where tom says this >
round_start()
{
activate_trig = getent("start_rounds", "targetname");
activate_trig waittill("trigger");
....
put this in your zombiemode.gsc folder
press control + F to find
Find "round_start" and keep searching until you see this
round_start()
{
Under the bracket put this activate_trig = getent("start_rounds", "targetname");
activate_trig waittill("trigger");
Save and Close
Now open your map in radiant and make a trigger_multiple and put it where you want it
Press N and Put Targetname > start_rounds
save build mod and then compile and youre done