It might not get removed because you have no entity which has the player pointer set to it.

Are you using the templates?

btw: that is no foreign language but c-script

Edit:
Ok I changed the code slightly.
It now checks the distance to the camera and not to the player entity:
Code:

---

define distance,skill1;
define max_dist,skill2;
define kill_skill,skill3;

action dist_object
{
  	my.max_dist = 300;
  	my.kill_skill = 0;
  	
  	//while my.kill_skill == 0 ..
  	while(!my.kill_skill)
  	{
  	   //store the distance in a skill
    	   my.distance = vec_dist(my.x,camera.x);
    	
    	   //compare
    	   if(my.distance > my.max_dist)
    	   { my.kill_skill = 1; } //its bigger so kill the while
  	}
  	//wait a frame
  	wait(1);
  	//remove me:
 	ent_remove(me);
}

undef distance;
undef max_dist;
undef kill_skill;

---