Detection wether char. controller hits char. controller

Good evening, i have got the following problem:

I am trying to make simple 2D Game, and while quite a lot of my scripts do work, there is one thing that does not:

The main character has a character controller, and so do the enemies, and for taking damage etc. I need a detection wether these character controllers collide.

After all, the do collide physically, and the enemies do not walk through the character as in my earlier tries, but I can't find the right function to detect this for my scripting ):

I think this is a rather simple task, but I don't get it^^

Sincerely

PS: I script in Javascript