[matsi]

So i made npc with default sas model:

spawn_npc( id )
{
    new Float:origin[ 3 ]
    
    entity_get_vector( id, EV_VEC_origin,origin )
    
    new ent = create_entity( "info_target" )
    
    entity_set_origin( ent, origin );
    origin[ 2 ]  += 100.0
    entity_set_origin( id, origin )
    
    entity_set_float (ent, EV_FL_takedamage, 1.0 )
    entity_set_float( ent, EV_FL_health, 100.0 )
    
    entity_set_string( ent, EV_SZ_classname, "test_npc" );
    entity_set_model( ent, "models/player/sas/sas.mdl" );
    entity_set_int( ent, EV_INT_solid, 2 )

    entity_set_byte( ent, EV_BYTE_controller1, 125 );
    entity_set_byte( ent, EV_BYTE_controller2, 125 );
    entity_set_byte( ent, EV_BYTE_controller3, 125 );
    entity_set_byte( ent, EV_BYTE_controller4, 125 );
    
    new Float:maxs[ 3 ] = { 16.0,16.0,36.0 }
    new Float:mins[ 3 ] = { -16.0,-16.0,-36.0 }
    entity_set_size( ent, mins, maxs )
    
    entity_set_float(ent,EV_FL_animtime,2.0)
    entity_set_float( ent, EV_FL_framerate, 1.0 )
    entity_set_int( ent, EV_INT_sequence, 0 );
    
    entity_set_float( ent, EV_FL_nextthink, halflife_time() + 0.01 )
    
    drop_to_floor( ent )
    return 1;
}

So how can i detect if its loosing hp ? And is my code correct for that use?