ups there is a lot of stuff in this code - i simplyfied him:
Code:

---

function player_fight()
{
	var animdist;
	var rdm;

	while(1)
	{
		if(mouse_left && mouse_mode == 0)
		{
				
			vec_set(temp.x,nullvector);
			temp.x = 48;					//sword range
			vec_rotate(temp.x,camera.pan);
			vec_add(temp.x,player.x);
				
			trace_mode = ignore_me + ignore_models;
			result = trace(my.x,temp.x);
				
			if(result != 0)
			{
				snd_play(hit_wav,10,0);	//sound for hitting a wall
			}else{
				snd_play(swing_wav,50,0);
			}
				

			//use this if you want area damage or use activate_shoot in trace above
				temp.pan = 90; 
				temp.tilt = 90;
	  			temp.z = 96;
	  			
	  		damage = player_dmg;  		//use your own var^^			
	  		scan_entity(camera.x,temp);
				

			animdist = 0;

			rdm += 1;
			if(rdm%2 == 0)
			{
				while(animdist < 100)
				{
					ent_animate(player_weapon,"attack_a",animdist,anm_cycle);
					animdist += 10 * time;
					wait(1);
				}	
			}
			if(rdm%2 == 1)
			{
				while(animdist < 100)
				{
					ent_animate(player_weapon,"attack_b",animdist,anm_cycle);
					animdist += 10 * time;
					wait(1);
				}			
			}
				
			while(mouse_left){wait(1);}		//delte this if you want to have a cycle - repeat swinging while pressing mouse
		}	

		wait(1);
	}
}

---