Check if unit of a side is in the radius of another unit

[Spriterfight 10]

I want that if the unit sees a target or detects a target then it will trigger an acton for him.My idea is i would create a radius for the unit attach to them and if the unit is in that radius then the trigger will activate.But i i have no idea how can i make an araea or radius for an unit via script ,i tried createMarker and attach it to the unit but markers can not be attached to units.Any idea?Maybe if i add an firednear eventhandler and filter the unit's side...

[pierremgi 4906]

use attachTo with trigger

 

[gc8 978]

Sounds like you could use the https://community.bistudio.com/wiki/knowsAbout command, to do this...