Tower Defence Unit Spawn Help

[Dark Soul]

Hi! Basically, I am currently working on a TD and I have a problem making a creep spawning system much like the ones in Gem TD and Sprout TD whereby when the wave starts, one unit at a time comes out of the spawning area and do not come out once the selected amount of units to be spawned has been met.

Anyone know how to do a trigger of this? By the way, I do not one a maul spawning system. Ty!

*Update- Solved*

 

[reason 3]

Take a look at this...TD


It is not protected,so you can have a look at its triggers.

*This map is not ready or suggested to be played...I just uploaded it here to help Dark Soul.