here is me code i am using:
Code:

---

entity player_weapon
{ 		
  type = <knife_arm.mdl>;
  layer = 0;
  view = camera;
  albedo = 50;
  ambient = -100;
  x = 32;
  y = -20;
  z = -19;
  pan = 10;
  tilt = 10;
  roll = -10;
}

function player_fight()
{
	var animdist;
	var mouse_left_pressed = 0;
	var rdm;
	while(1)
	{
		if(mouse_left && mouse_mode == 0)
		{
			
			temp.pan = 10; 
			temp.tilt = 10;
	  		temp.z = 128;
	  		
	  		indicator = _click;
	  		scan_entity(camera.x,temp);
			
			
			//snd_play(click_wav,100,0);
			
			if(item_player_weapon && mouse_left && animdist == 0)
			{
				
				vec_set(temp.x,nullvector);
				temp.x = 48;
				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);
				}else{
					snd_play(swing_wav,50,0);
				}
				
				temp.pan = 90; 
				temp.tilt = 90;
	  			temp.z = 96;
	  			
	  			damage = player_dmg;  			
	  			scan_entity(camera.x,temp);
				
				rdm += 1;//int(random(2));
				if(rdm%2 == 0)
				{
					while(animdist < 100)
					{
						ent_animate(player_weapon,"attack_a",animdist,anm_cycle);
						animdist += 10 * time;
						wait(1);
					}	
						
					ent_animate(player_weapon,"attack_a",100,anm_cycle);
					animdist = 0;
				}
				if(rdm%2 == 1)
				{
					while(animdist < 100)
					{
						ent_animate(player_weapon,"attack_b",animdist,anm_cycle);
						animdist += 10 * time;
						wait(1);
					}	
						
					ent_animate(player_weapon,"attack_b",100,anm_cycle);
					animdist = 0;					
				}
				
			}
			while(mouse_left){wait(1);}
		}	
		wait(1);
	}
}

---

its alittlebit long but works fine^^ (it use two different attack-animations)